List of U Idioms:

These U idioms are the most commonly used idioms beginning with the letter "u" of course. That is, the main word in the starts with a "u"). If you want to learn idioms beginning with other letters, click here to go to the main idioms page

Before we get started, in case you forgot, an idiom is a group of words whose meaning is different from the individual words if you looked them up separately in the dictionary.

I always recommend that my student concentrate on understanding idioms rather than trying to use them at the beginning. However, to become fluent in the language, eventually you will want to be able to use them. You can practice by writing a sentence (or two!) in the comments because I am here to help correct any mistakes you might make. Okay? So... here's the list!

U Idioms


unaccustomed to someone/something: not used to something.

  • I moved here three years ago and I’m still unaccustomed to this cold weather.
  • I’m unaccustomed to hearing  women using bad language.


under arrest:  when the police take someone into custody (arrests them) and takes them to the police station.

  • The police chased the criminals for five blocks and then place them under arrest.

under certain circumstances:  in certain situations.

  • Under certain circumstances  you can attend the training for free.
  • It’s possible to see the mountains from here under certain circumstances.

under scrutiny:  being closely watched, examined or investigated.
After I was caught smoking, my parents of put me under a lot more scrutiny.

  • The police had three people under close scrutiny  for the theft of the art gallery’s paintings.

under construction:  being built.

  • This website is still under construction.
  • There’s a lot of traffic on the freeway because that bridge is under construction.

under cover:  hidden and being done secretly (especially used with police and law enforcement).

  • See that woman who looks like a prostitute? She’s really a police officer working under cover.
  • Many security guards at the shopping mall work under cover.

under fire:  being attacked by firearms or words.

  • When I met my boyfriend’s parents they had me under fire  the entire evening.
  • The robbers were under fire  for 20 minutes before they put down their weapons and surrendered to the police.

under oath:  having made a formal promise or taken an oath to say the truth.

  • The judge reminded the witness that he was under oath  and should tell the truth.

under one’s belt:  having the experience of doing something.

  • I felt a lot more confident after I got a year of teaching under my belt.

under one’s breath:  speaking very quietly with a whisper (low voice).

  • Whenever I asked my kids to do their chores they complain under their breath.

under one’s nose:  something easily seen or found.

  • She was looking for the perfect husband for several years when she realized her dream man—her next door neighbor—was under her nose  the whole time.
  • I can’t find my sunglasses! They’re right under your nose, on top of your head that is!

under pressure:  experiencing a lot of stress and anxiety.
  • Our manager is under a lot of pressure  since the new director doubled our sales target.
  • Most high school seniors are under pressure  because they have to do well in school and get into a good college.

under the circumstances:  because of a certain condition, situation or circumstance.

  • I heard your husband’s brother recently died and I’m sure that must be difficult. Yes, it is but under the circumstances  he’s actually doing very well.

under the influence (of someone or something): experiencing the effects of drugs, alcohol or the control of a powerful person.

  • Too many young pop singers and actors are arrested for driving under the influence  these days.
  • It’s important to monitor who your children’s friends are so that they don’t become under the influence of bad kids.

under the table:  in secret (often doing something illegal).

  • Unfortunately, politicians sometimes award contracts to companies under the table.
  • When we got to the restaurant there was a long line, so I slipped a $20 bill to the hostess under the table and we were seated at a table 10 minutes later.

under the weather:  feeling sick, especially sick with the flu or a common cold.

  • I called in sick to work today because I was feeling under the weather.
  • No, it’s nothing serious I just feel under the weather today.


until all hours:  until very late.

  • We were up until all hours  last night finishing the report before the deadline.
  • Our neighbors are so annoying, they play music really loud until all hours  during the week.

until hell freezes over:  forever.

  • Those two will hate each other until hell freezes over.
  • I’m sure politicians will be liars until hell freezes over.

until someone is blue in the face:  talking for a very long time.

  • I explained how to operate the machine until I was blue in the face.
  • I yelled at my son for not coming home last night until I was blue in the face.


in unison:  together at the same time.

  • The children’s choir wasn’t very good today — they were hardly in unison.
  • When I asked my kids if they wanted to go to the zoo, they screamed “yes” in unison.


do the unthinkable:  to do something that’s not expected.

  • When I woke up this morning I discovered my husband had done the unthinkable; the dishes were done, the floor had been cleaned and the children’s lunches were packed.
  • When people are very drunk they sometimes do the unthinkable.


not up to something:  don’t feel like doing something.

  • If you’re not up to going out  tonight, let’s order a pizza and watch TV.
  • I’m not up to exercising  today but I’m definitely going tomorrow no matter what.

right up there with someone/something:  is good/bad as someone/something else.
  • To me doing homework is right up there with  having a tooth pulled by the dentist.
  • Did you see her new ranking? She’s right up there with  the top tennis players now

up against someone/something:  in opposition with someone/something.

  • In her next match, she’s up against  a much more difficult player.
  • I can’t go out tonight because I’m up against  a tough deadline and have to work.

up and around/about:  out of bed after illness and moving again.

  • After the surgery, she was up and about  after just a week.
  • It’s so nice to be up and around  after being in bed with the flu for a week.

up and coming:  newly starting to be popular or successful.

  • Listen to this up-and-coming  singer, she’s fantastic.

up and running:  functioning, working properly.

  • Luckily, the technician got the Internet up and running  again after 20 minutes.
  • She had hoped to have the new department up and running  by the new year, but everything was behind schedule.

up for something: enthusiastic or interested about something.

  • Are you up for going skiing  this weekend?
  • If anyone’s up for a movie  tonight, I’m going to see the latest in the Spiderman series.

up for grabs:  possible for anyone to have.

  • The director just announced this month’s contest and a new MacBook is up for grabs.

up front:  clear and honest about something.

  • I wish you had been up front  about how big your house was because I won’t be able to finish the painting job by the date you wanted.
  • I want to be up front  about the amount of travel involved in this job: you’ll be expected to travel at least one week every month.

up in arms:  upset, angry.

  • The entire team was up in arms  when the coach said they would have to practice an extra 30 minutes each day.
  • I’m up in arms  about the new fees my bank is going to start charging.

up in the air:  not decided about something, unsettled.

  • Our plans for the New Year’s are still up in the air  but I’ll let you know what we decide in case you want to join us.
  • The person will select to replace the cleaner is still up in the air  but we have a good list of candidates to choose from.

up in years:  old/elderly.

  • She’s up in years  now but everyone thinks she’s 20 years younger than she is.
  • When I get up in years  I want to move somewhere where there’s a warm climate.

up one’s alley:  an activity someone likes and is good at.

  • I hate fixing things but luckily home repair is up my wife’s alley.
  • Cooking is up her alley so she decided to quit her job and open a catering business.

up the creek:  in trouble or a difficult situation.

  • I’m up the creek, my credit card bill is due in two days but I don’t get paid until next week.
  • We missed our flight and now were up the creek  because there are no available seats on any flights until next Tuesday.

up to someone:  to be responsible to do something.

  • It doesn’t matter what I think, the decision is up to my boss.
  • If you want to lose weight, it’s up to you  to eat better and start exercising.

up to something:  secretly doing or planning something.

  • Whenever it’s quiet at home I know my kids are up to something.
  • When no one wished me a happy birthday all morning I knew my team was up to something.

up-to-date:  to the latest standards.

  • These figures don’t look right. Can you make sure they are up-to-date?
  • It’s important to keep your software up-to-date  so that your protected against new viruses.

up to it:  having the desire, interest or capability to do something.

  • I really should do some financial planning but I’m not up to it.
  • I just asked Suzanne to come with us to the shopping mall but she’s not up to it.

Up to no good:  doing something wrong or bad.

  • My puppy is always up to no good  so I have to watch them very carefully.
  • My husband has been coming home very late and I’m worried he’s up to no good.

up to one’s eyeballs:  a lot of something undesirable.

  • During tax season, accountants are up to their eyeballs with work.
  • I’m up to my eyeballs in debt and need to stop using my credit cards.

up-to-the-minute: the most recent or latest.

  • At Channel 5 news, we deliver up-to-the-minute  reports about traffic, weather and news that’s important to you.
  • Check the leaderboard for up-to-the-minute  results in the tournament.

up until:  until, to a certain time.

  • I was up until  2 AM finishing my homework.
  • Up until  we got married he was a super loving guy.


have the upper hand:  having power, control or advantage.

  • Children who come from wealthy families have the upper hand  when applying to college.
  • My dogs are always fighting but this one has the upper hand  because he’s stronger and faster.


ups and downs:  good and bad things; both good and bad times.

  • Even the best marriages have their ups and downs.
  • I really liked his talk because he discussed both the ups and downs  of being a famous actor.


upside down: with the top side facing downward; changing something completely.

  • Her life turned upside down  after having twins.
  • If you hang those roses upside down, they’ll dry out in a perfect bouquet.


uptight:  worried and anxious.

  • My last girlfriend was gorgeous but she was so uptight  and my current girlfriend is very average looking but completely confident about her looks.
  • My mother is very uptight  about my grades at school.


use every trick in the book: try everything or every possible method.

  • She finally won but it was a tough match and she had to use every trick in the book  to beat her opponent.
  • I’m not going to stop until I’ve used every trick in the book.

it’s no use/there’s no use:  there’s no reason to do or try something.

  • I’ve tried to talk to her but it’s no use — she’s inconsolable that he broke up with her.
  • There’s no use begging me to help because registration ended yesterday and the class is full.

use up:  to finish all of something until nothing remains.

  • Help! Someone used up  all the toilet paper and didn’t replace the roll with a new one.
  • I'm exhausted; I used up  all my energy mowing the lawn this afternoon.


used to (do something):  had the habit of doing something in the past.

  • I used to hate  spinach, but now it’s one of my favorite vegetables.
  • When I was a kid I used to live  in Nigeria for five years because my father worked for an oil company.

used to (doing) something:  familiar with something; accustomed to something.

  • I know you’re used to eating  sugary foods but you’re going to have to change your diet if you want to get well.
    Once you get used to using this software, you’re going to love it.


as usual:  as expected, as normally happens.

  • If he’s late as usual, this time I’m not going to wait for him.
  • Congratulations! Your performance was excellent as usual

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You can also find many idiom definitions with the different online learner's dictionaries.

Your turn: Pick an expression from this U idioms list and practice

Don't worry if you make a mistake, I will help correct your sentence. It's that easy. Please write an example or two by picking any expression from the idiom list above.

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