These idioms are compiled from the Cambridge International Dictionary.The Cambridge International Dictionary explains over 7,000 idioms current in British, American and other English speaking countries, helping learners to understand them and use them with confidence. The Cambridge Dictionary, based on the 200 million words of English text in the Cambridge International Corpus, unlocks the meaning of more than 5,000 idiomatic phrases used in contemporary English. Full-sentence examples show how idioms are really used.
The Cambridge University Press is respected worldwide for its commitment to advancing knowledge, education, learning and research. It was founded on a Royal Charter granted to the University by Henry VIII in 1534 and has been operating continuously as a printer and publisher since the first Press book was printed in 1584.
U-turn: If a government changes its position radically on an issue, especially when they have promised not to do so, this is a U-turn.
Ugly as a stick: (USA) If someone is as ugly as a stick, they are very ugly indeed.
Ugly duckling: An ugly duckling is a child who shows little promise, but who develops later into a real talent or beauty.
Uncharted waters: If you're in uncharted waters, you are in a situation that is unfamiliar to you, that you have no experience of and don't know what might happen. (Unchartered waters is an incorrect form that is a common mistake.)
Uncle Sam: (USA) Uncle Sam is the government of the USA.
Under a cloud: If someone is suspected of having done something wrong, they are under a cloud.
Under a flag of convenience: If a ship sails under a flag of convenience, it is registered in a country where taxes, etc, are lower than in the country it comes from, so if someone does something under a flag of convenience, they attempt to avoid regulations and taxes by a similar means.
Under false colors: If someone does something under false colors/colors, they pretend to be something they are not in order to deceive people so that they can succeed.
Under fire: If someone is being attacked and criticised heavily, they are under fire.
Under lock and key: If something is under lock and key, it is stored very securely.
Under someone's heel: If you are under someone's heel, they have complete control over you.
Under the radar: If something slips under the radar, it isn't detected or noticed.
Under the table: Bribes or illegal payments are often described as money under the table.
Under the weather: If you are feeling a bit ill, sad or lack energy, you are under the weather.
Under the wire: (USA) If a person does something under the wire, they do it at the last possible moment.
Under your breath: If you say something under your breath, you whisper or say it very quietly.
Under your nose: If something happens right in front of you, especially if it is surprising or audacious, it happens under your nose.
Under your skin: If someone gets under your skin, they really annoy you.
Under your thumb: Someone who is manipulated or controlled by another person is under his or her thumb.
Uneasy lies the head that wears the crown: This means that people with serious responsibilities have a heavy burden.
Unwavering loyalty: Unwavering loyalty does not question or doubt the person or issue and supports them completely.
Up a river without a paddle: If you up a river without a paddle, you are in an unfortunate situation, unprepared and with none of the resources to remedy the matter.
Up for grabs: If something is up for grabs, it is available and whoever is first or is successful will get it.
Up in the air: If a matter is up in the air, no decision has been made and there is uncertainty about it.
Up sticks: (UK) If you up sticks, you leave somewhere, usually permanently and without warning- he upped sticks and went to work abroad.
Up the ante: If you up the ante, you increase the importance or value of something, especially where there's an element of risk as the term comes from gambling, where it means to increase the stake (the amount of money bet).
Up the creek: If someone or something is up the creek, they are in real trouble. 'Up the creek without a paddle' is an alternative, and 'up shit creek (without a paddle)' is a ruder form.
Up the duff: (UK) If a woman is up the duff, she's pregnant.
Up the spout: (UK) If something has gone up the spout, it has gone wrong or been ruined.
Up the stick: (UK) If a woman is up the stick, she's pregnant.
Up the wall: If someone goes up the wall, they get very angry.
Up the wooden hill: When you go up the wooden hill, you go up the stairs to bed.
Up to scratch: If something doesn't come up to scratch, it doesn't meet the standard required or expected.
Up to snuff: If something isn't up to snuff, it doesn't meet the standard expected.
Up to speed: If you bring someone up to speed, you update them on something.
Up to the eyes: You are up to your eyes in something, you are deeply involved or to have too much of something like work. ('Up the neck', 'up to the eyeballs' and 'up to the ears' are also used.)
Up to the neck: If someone's in something up to the neck, they are very involved in it, especially when it's something wrong.
Up to your neck: If someone is very involved in something, they are up to their neck in it, especially if it is something bad or immoral.
Up with the lark: If you get up very early, you're up with the lark.
Upper crust: The upper crust is the upper classes and the establishment.
Upper hand: If you have the upper hand, you have the advantage.
Upset the apple cart: If you upset the apple cart, you cause trouble and upset people.