U(adj) :(Br)<rarely used>(capital) (esp. of words or behavior) of or belonging to upper social class; socially correct. _It's not U to call a lieutenant "sergeant."

(as) ugly as sin(adj) :extremely ugly.

ugly customer(n) :a person difficult to handle.

ugly duckling(n) :a person who is less talented, skillful, beautiful, etc. than others but is in the way to improve his/her quality.

ultimate(adj.) :(the) best. _The --- dictionary.

um and aah(v) :to speak unclearly and without saying exactly what one wants to say, esp. to save time before making a decision. also hum/hem and haw.

umpteen(adj) :great number of; innumerable. _Haven't I told you --- times, that you shouldn't leave your room before you order it.

'un(pron) :one. _That's a good'un.

uncle(n) :(used to address) an elderly man.

I'll be a monkey's uncle!(interj) :used to express great surprise.

say uncle(v) :(Am)to yield; admit defeat.

Uncle Sam(n) :the United States of America.; the US.

under-the-counter(adj) :(sthg bought or sold) in illegal ways. _- I want to buy a small radio, if you find a shop who holds under-the-counter sales I can buy it cheaper.

undergrad(n) :infml for undergraduate(=a student who studies in the university and has not yet passed his final examinations.

underpinnings(n) :the legs.

underwhelm(v) :<humor>to fail to overwhelm (sb) with enthusiasm, excitement, etc. _The performer --- the audience.

undies(n) :women's or children's underwears.

unearthly(adj) :(of time) very inconvenient; unreasonable; absurd. _What an --- time to go on a picnic?

unflapppable(adj) :(of a person) unlikely to get into panic.

un-get-at-able(adj) :not easily obtained; unaccessible.

unglue(v) :to cause sb to be very excited or upset.

ungodly(adj) :1-annoying; shocking. 2-inconvenient; unreasonable.

unholy(adj) :not sensible; unreasonable.

unique(adj) :extraordinary; unusual. _She had a --- clothing at the party.

unisex(adj) :(usu. of clothes) worn by both male and female. _a --- sweater.

unload(v) :[on]to dispose or get rid of sthg unwanted. _Don't --- that responsibility on me.

unspeakable(adj) :unpleasant; terrible. _--- remarks.

unwind(v) :to relax.

What's up? :What's going on?; What's the matter?

up(adj) :in court. _The famous singer is up in court.

up to(adv) :about to do (sthg bad). _I'll go and look at what the children are ---, they're very silent.

Up with :(used to express one's agreement or approval) We approve of. _The people were speaking up: --- the human rights!

Up yours!(interj) :<slang>(used as an answer to a criticism to express strong disagreement or rejection) Fuck off!; Go to hell! _Hey, if you continue to harass students, I will throw you out of the classroom. - ---, man, I am not here for my own will. also up yours and twist it! <This phrase, often used with an offensive sign made by the hand, is not recommended for use by foreign students>

be well up in/on(v) :to be well-informed about.

up and about(adv) :able to walk esp. after an illness.

up(v) :1-to increase; make higher. _The government --- the taxes. 2-(used before and in order to add force to the action.) _As she heard the noise, she upped and got out of the door.

on the up-and-up(adj,adv) :1-(Br)(adv) :going ahead successfully. 2-(adj) :(Am)honest.

upbeat(adj) :very happy; cheerful.

an up-and-a-downer(n) :a noisy and violent quarrel or fight.

(down) on one's uppers(adj) :<rarely used>very poor.

upper crust(n) :the richest and highest social class.

wrong in the upper storey(adj) :having a confused state of the mind.

uppish(adj) :<derog>having a very great opinion of oneself; snobbish; conceited.

uppity(adj) :<derog>snobbish; self-assertive.

ups and downs(n) :good and bad periods, esp. in succession. _Life is full of ups and downs, so you shouldn't be discouraged, everything will be all right!.

upstage(adj) :snobbish; uppity.

kick sb upstairs(v) :to promote sb to a higher position but that gives less influence or power.

quick/slow on the uptake(adj) :quick/slow in understanding or comprehension. _I told him three times, but unfortunately, he's a bit slow on the uptake.

uptight(adj) :very anxious, worried, or likely to be angry.

have no use for(v) :to have no liking for; dislike.

U-turn(n) :<derog>complete change in one's opinions, actions, etc.