on request When asked for, as in The agreement states that the rights on this book revert to the author on request. [c. 1800] Also see BY REQUEST.
on sale At a reduced price, as in These rugs have been on sale for a month. The use of sale for disposing of goods at lowered prices dates from about 1860.
on schedule At the announced or expected time, as in Her first baby arrived right on schedule. Originally alluding to published railroad timetables, this expression dates from the late 1800s.
on second thought Resulting from a revised opinion or change of mind, as in I thought I’d go to the movies, but on second thought I’d rather stay home. Similarly, have second thoughts means “change one’s mind,” as in I’ve had second thoughts about moving to Florida. This idiom alludes to ideas that come later. [Mid-1600s]
on sight Also, at sight. Immediately upon seeing, as in The soldiers threatened to shoot looters on sight, or He’s able to multiply those three-digit figures at sight. [Second half of 1400s]
on someone’s → In addition to the following idioms beginning with ON SOMEONE’S, also see under ON ONE’S.
on someone’s back Also, on someone’s case. → See under OFF SOMEONE’S BACK.
on someone’s coattails Also, on the coattails of. Owing to another person’s popularity or merits. For example, He won the cabinet post by hanging on the senator’s coattails, or He was elected to office on the coattails of the governor. This expression, with its graphic image, dates from the mid-1800s, when coats with tails were in fashion.
on someone’s nerves → See GET ON SOMEONE’S NERVES.
on someone’s side In support of someone’s views or interests, as in I’m glad you’re on my side in this debate, or With the Canadians on our side, we should be able to persuade the Mexicans of a North American policy. [1300s]
on speaking terms 1. Friendly enough to exchange superficial remarks, as in We’re on speaking terms with the new neighbors. 2. Ready and willing to communicate, not alienated or estranged. For example, We are on speaking terms again after the quarrel. Both senses of this idiom commonly occur in the negative, as in Brett and his brother haven’t been on speaking terms for years. The idiom was first recorded in 1786.
on spec Done on a speculative basis; with no assurance of profit. For example, We didn’t design our house; the builder built it on spec. The use of spec as an abbreviation for speculation dates from the late 1700s.
on standby Ready and waiting, as in We’ve got three more painters on standby. This expression originated in the navy in the 1940s, where it referred to someone being ready to come on duty as soon as required. From about 1960 it began to be widely used in aviation for a passenger waiting to take the first available seat on a full flight.
on strike Engaged in a work stoppage, as in The auto workers were on strike for the entire summer. The use of strike for a concerted labor stoppage undertaken to gain concessions from employers dates from the early 1800s. Today it is also used more loosely, as in Where washing dishes is concerned, Mom has announced that she’s on strike. Also see GO OUT, def. 4.
on sufferance Barely tolerated; agreed to but unwillingly. For example, They rarely put a non-academic on the panel, so obviously I was there on sufferance. This expression uses sufferance in the sense of “toleration,” a usage obsolete except in this idiom. [Mid-1500s]
on tap Available for immediate use, ready, as in We have two more trumpeters on tap for the parade. This metaphoric expression alludes to a beverage such as beer that is ready to be drawn from a cask. [Mid-1800s]
on target Completely accurate, wholly valid, as in Our cost estimates were right on target, or His criticisms were on target. This seemingly old expression dates only from the mid-1900s, and the colloquial use of target for a goal one wishes to achieve dates from about 1940.
on tenterhooks In a state of painful suspense, as in We were on tenterhooks all through the game, hoping against hope that our team would win. This expression alludes to hooks that formerly were used to hold newly woven cloth that was being stretched on a frame. Their name has long survived this method of manufacture. [Mid-1700s]
on the air → See under OFF THE AIR.
on the alert Watchful, fully prepared, as in The inspectors are always on the alert for a manufacturing error. [Late 1700s]
on the average As a rule, usually, as in On the average, about 15 percent of the freshmen class will drop out before graduation. This expression uses average in the sense of “a norm or standard.” [First half of 1700s]
on the ball, be Also, have a lot or something on the ball. Be especially capable or efficient, as in These programmers really have a lot on the ball. This term originated in baseball, where it was used for throwing a pitch with exceptional speed, spin, or some other deceptive motion. [Slang; early 1900s]
on the bandwagon, get Also, climb or hop or jump on the bandwagon. Join a cause or movement, as in More and more people are getting on the bandwagon to denounce cigarette smoking. This expression alludes to a horsedrawn wagon carrying a brass band, used to accompany candidates on campaign tours in the second half of the 1800s. By about 1900 it was extended to supporting a campaign or other cause.
on the barrel → See CASH ON THE BARRELHEAD.
on the beam → See under OFF THE BEAM.
on the bench 1. Presiding as judge in a law court, as in Lawyers are very careful when Judge Brown is on the bench. This usage alludes to the seat occupied by a judge. [Late 1200s] 2. Waiting for a chance to participate; also, removed from participation. For example, Mary complained that all her colleagues were going to the sales conference while she was left on the bench. This usage comes from baseball and other sports, where players not deemed ready or competent to play sit on a bench watching the game. [Early 1900s]
on the blink Also, on the bum or fritz. Malfunctioning, out of order, broken, as in The TV is on the blink again, or You drive—our car’s on the bum. The first of these slangy expressions dates from the late 1800s and possibly alludes to an electric light that flickers on and off (“blinks”); the second, from the same period, possibly is derived from bum in the sense of “a contemptible person”; the third, fritz, dating from about 1900, is of unknown origin.
on the block 1. put or go on the block. Offer for sale, as in These paintings will all be put on the block. This usage alludes to the auction block, the platform from which the auctioneer sells, so called since the mid-1800s. 2. put one’s head on the block. Take a great risk, make oneself vulnerable, as in I’m not going to put my head on the block just to save her reputation. This usage alludes to the executioner’s block, on which victims are beheaded, so called since the mid-1500s.
on the brain → See ON ONE’S MIND.
on the bum → See under ON THE BLINK.
on the button Exactly right, precisely, as in Her review of the book was right on the button, or We’re supposed to be there at six o’clock on the button. This term may come from boxing, where a punch on the button means “a punch on the chin.” [Colloquial; c. 1900] Also see ON THE DOT.
on the carpet → See CALL ON THE CARPET.
on the chance that On the possibility that, as in I came early on the chance that we might have time to chat. This phrase uses chance in the sense of “a possibility or probability for some event,” a usage dating from the late 1700s. It is sometimes put as on the off chance, meaning “on the slight but unlikely possibility,” as in I came late on the off chance that I could avoid Thomas. The addition of off in the sense of “remote” dates from the mid-1800s.
on the cheap Economically, at very little cost, as in We’re traveling around Europe on the cheap. [Colloquial; mid-1800s]
on the chin → See TAKE IT ON THE CHIN.
on the contrary It’s the opposite, as in Is his shoulder hurting?—On the contrary, it’s all better, or We thought you didn’t like opera.—On the contrary, I love it. This phrase, at first put as by or for or in the contrary, dates from the late 1300s; on has been used since the mid-
1800s.
on the cuff 1. On credit, as in He tried to hire a detective on the cuff. It is sometimes put as put on the cuff, meaning “extend credit to,” as in They asked to be put on the cuff until they got their monthly check. This usage probably alludes to the practice of recording bar tabs on the bartender’s cuff. Also see OFF THE CUFF. [Slang; 1920s] 2. Free of charge, as in We hope these drinks are on the cuff. [Slang; 1920s] Also see ON THE HOUSE.
on the defensive Prepared for withstanding aggression or attack, as in The debate team’s plan was to keep their opponents on the defensive, or This teacher put students on the defensive about their mistakes. [c. 1600]
on the dot Exactly on time, as in We had to be there at eight on the dot. The dot in this idiom is the mark appearing on the face of a watch or clock indicating the time in question. It may come from the earlier to a dot, meaning “exactly” since the early 1700s but no longer heard today. [c. 1900] Also see ON THE BUTTON.
on the double Very quickly, as in You’d better get here on the double. This expression, also put as at the double, came from the military, where it means “double time”—that is, marching twice as fast as normally. [Early 1800s]
on the edge 1. In a precarious position; also, in a state of keen excitement, as from danger or risk. For example, When the stock market crashed, their whole future was on the edge, or Skydivers obviously must enjoy living on the edge. 2. on the edge of. On the point of doing something, as in He was on the edge of winning the election when the sex scandal broke. [c. 1600] Both def. 1 and 2 allude to the danger of falling over the edge of a precipice.
on the eve of Just prior to, as in On the eve of the conference the main speaker backed out. This expression uses eve, literally “the night before,” more loosely. [Late 1700s]
on the face of it Seemingly, based on available evidence, as in On the face of it this project should break even in six months. This idiom uses face in the sense of “a superficial view.” [Early 1700s]
on the fence, be Also, straddle the fence. Be undecided, not committed, as in I don’t know if I’ll move there; I’m still on the fence, or He’s straddling the fence about the merger. This picturesque expression, with its implication that one can jump to either side, at first was applied mainly to political commitments. [Early 1800s]
on the fly In a hurry, on the run, as in I picked up some groceries on the fly. The transfer of this expression, which literally means “in midair or in flight,” dates from the mid-1800s.
on the fritz → See under ON THE BLINK.
on the go In constant activity, very busy, as in I’m exhausted—I’ve been on the go since eight this morning. [Mid-1800s]
on the heels of Also, hard on the heels of. Directly behind, immediately following, as in Mom’s birthday comes on the heels of Mother’s Day, or Hard on the heels of the flood there was a tornado. The hard in the variant acts as an intensifier, giving it the sense of “close on the heels of”. [Early 1800s] Also see AT SOMEONE’S HEELS.
on the horizon Within view, not too far away, as in The analysts see a huge rise in the stock market on the horizon.
on the horns of a dilemma → See HORNS OF A DILEMMA.
on the hour At every hour exactly; one o’clock, two o’clock, and so on. For example, The shuttle to New York departs on the hour. An extension of this idiom is every hour on the hour, meaning every time the clock’s big hand reaches twelve, as in The bus passes by the house every hour on the hour.
on the house At the expense of the establishment, as in This hotel serves an afternoon tea that’s on the house. This idiom uses house in the sense of “an inn, tavern, or other building serving the public.” [Late 1800s]
on the in, be Have inside information, as in She was too new to the firm to be on the in for policy changes. [Colloquial; c. 1930] Also see GET AN IN WITH; IN ON.
on the increase Growing, especially in frequency of occurrence, as in Violent crime is on the increase. [Mid-1700s]
on the inside In a position of confidence or influence, as in The new reporter said he got his facts from at least one official on the inside. [c. 1930]
on the job 1. At work, busy, as in We’ve got three men on the job. [Late 1800s] 2. Paying close attention, alert, as in Trust Jim to find out the details—he’s always on the job.
on the lam Running away, especially from the police, as in He’s always in some kind of trouble and perpetually on the lam. The origin of this slangy term of the 1800s is not known.
on the level Honest, straightforward, sincere, as in You can believe her—she’s on the level. This expression may have come from Freemasonry, where the carpenter’s level symbolizes integrity. [Late 1800s]
on the line → See LAY ON THE LINE.
on the lines of → See ALONG THE LINES OF.
on the lookout Also, on the watch. Vigilant, alert, as in Be on the lookout for the twins—they’re somewhere on this playground, or He was on the watch for her arrival. Both phrases were originally used with upon. Upon the lookout was originally nautical usage, meaning “on duty being watchful” (as for another ship, rocks, or land); it appeared in the mid-1700s, and on replaced upon about a century later. Upon the watch was first recorded in Daniel Defoe’s Robinson Crusoe (1719), and on the watch in Jane Austen’s Sense and Sensibility (1797).
on the loose 1. At large, free, as in That dog of theirs is on the loose all the time. [Second half of 1800s] 2. Acting without restraint, as in After the game the players were in town, on the loose. [Mid-1700s]
on the make 1. Seeking personal gain, as in Tom’s a young man on the make—he doesn’t care whom he offends. [Slang; second half of 1800s] 2. Looking for sexual conquest, as in After several affairs, Peter got the reputation of being a man on the make. [Slang; c. 1920]
on the map → See PUT ON THE MAP.
on the mark → See under OFF THE MARK.
on the market For sale; also, available for buying. For example, We’ve put the boat on the market, or This is the only tandem bicycle on the market right now. This phrase, first put as in the market, dates from the late 1600s; the first recorded use of the phrase with on was in 1891. Also see DRUG ON THE MARKET.
on the mend Recovering one’s health, as in I heard you had the flu, but I’m glad to see you’re on the mend. This idiom uses mend in the sense of “repair.” [c. 1800]
on the money Also, right on the money. Exact, precise, as in Your estimate is right on the money. This term alludes to a winning bet in horse racing. [Slang; 1940s]
on the move 1. Busily moving about, very active, as in A nurse is on the move all day long. [Mid-1800s] Also see ON THE GO. 2. Going from one place to another, traveling, as in Our troops are on the move again, or Ruth and Dick are always on the move, never staying put for more than a month or two. [Late 1700s] 3. Making progress, advancing, as in Their technology is clearly on the move.
on the nail 1. Immediately, without delay, as in He paid us back on the nail. [c. 1600] 2. Under discussion or consideration, as in The subject of the budget deficit has been on the nail for some time. [Late 1800s] The precise allusion in these expressions has been lost. Neither has any connection to hit the nail on the head (see under HIT THE BULL’S-EYE).
on the nose Exactly, precisely; especially, at the appointed time or estimated amount. For example, The busload of students arrived at the museum at ten o’clock right on the nose, or He guessed the final score on the nose. This term, like ON THE BUTTON, may come from boxing, where the opponent’s nose is a highly desired target. [c. 1930]
on the off chance → See under ON THE CHANCE THAT.
on the one hand Also, on one hand. As one point of view, from one standpoint. This phrase is often paired with on the other hand to indicate two sides of an issue. For example, On the one hand this car is expensive; on the other hand, it’s available and we need it right now. [First half of 1600s]
on the order of 1. Approximately, as in We need on the order of three cases of wine for the reception. 2. Like, of a kind similar
to, as in Their house is on the order of a colonial saltbox. [c. 1900]
on the other foot → See SHOE IS ON THE OTHER FOOT.
on the other hand → See under ON THE ONE HAND.
on the outs No longer on friendly terms, as in They’ve been on the outs with their in-laws for years. This idiom appeared in the early 1900s and derives from the synonymous at outs, first recorded in 1824.
on the part of → See FOR ONE’S PART.
on the point of Also, at the point of. On the verge of, close to, as in I was on the point of leaving when the phone rang. The first term dates from the late 1200s, the second from the first half of the 1500s.
on the prowl Actively looking for something, as in Their underpaid computer programmers are always on the prowl for better jobs. This idiom transfers an animal’s search for prey to human pursuits that are usually less blood-thirsty. [c. 1800]
on the qui vive On the alert, vigilant, as in The police have been warned to be on the qui vive for terrorists. This expression, containing the French words for “[long] live who?” originated as a sentinel’s challenge to determine a person’s political sympathies. The answer expected of allies was something like vive le roi (“long live the king”). It was taken over into English with its revised meaning in the early 1700s, the first recorded use being in 1726.
on the Q.T. Secretly, as in They told her on the Q.T. that she was being promoted. This slangy term, in which Q.T. is an abbreviation for “quiet,” was first recorded in 1870.
on the rack Under great stress, as in I was on the rack while I waited for the test results. This expression, alluding to a medieval instrument of torture to which the victim was fastened and stretched, has been used figuratively since the late 1500s. Shakespeare had it in The Merchant of Venice (3:2): “Let me choose, for as I am I live upon the rack.”
on the rebound Reacting to or recovering from an unhappy experience, especially the end of a love affair. For example, A month after breaking up with Larry, Jane got engaged to Bob, a classic case of being on the rebound. This metaphoric term, alluding to the bouncing back of a ball, has been used in the present sense since the mid-1800s, although rebound alone had been used figuratively for much longer.
The American Heritage Dictionary of Idioms Page 87