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U

1 American  
[yoo] / yu /
Or u

noun

plural

U's, Us, u's, us
  1. the 21st letter of the English alphabet, a vowel.

  2. any spoken sound represented by the letter U or u, as in music, rule, curious, put, or jug.

  3. something having the shape of a U .

  4. a written or printed representation of the letter U or u.

  5. a device, as a printer's type, for reproducing the letter U or u.


U 2 American  
[yoo] / yu /

pronoun

Informal.
  1. you.

    Shoes Fixed While U Wait.


U 3 American  
[yoo] / yu /

adjective

Informal.
  1. characteristic of or appropriate to the upper class, especially of Great Britain.


U 4 American  
[oo] / u /

noun

  1. a Burmese title of respect applicable to a man: used before the proper name.


U 5 American  
Symbol.
  1. (on a packaged product) certified as kosher by the Union of Orthodox Hebrew Congregations.

  2. the 21st in order or in a series.

  3. Chemistry. uranium.

  4. Biochemistry. uracil.

  5. Thermodynamics. internal energy.

  6. British. a designation for motion pictures determined as being acceptable for viewing by all age groups.


u. 6 American  

abbreviation

  1. and.


u. 7 American  

abbreviation

  1. uniform.

  2. unit.

  3. unsatisfactory.

  4. upper.


U. 8 American  

abbreviation

  1. and.


U. 9 American  

abbreviation

  1. uncle.

  2. uniform.

  3. union.

  4. unit.

  5. united.

  6. university.

  7. unsatisfactory.

  8. upper.


U 1 British  

symbol

  1. united

  2. unionist

  3. university

    1. universal (used to describe a category of film certified as suitable for viewing by anyone)

    2. ( as modifier )

      a U film

  4. chem uranium

  5. biochem uracil

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

abbreviation

  1. text messaging you

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

adjective

  1. old-fashioned (esp of language habits) characteristic of or appropriate to the upper class Compare non-U

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
U. 2 British  

abbreviation

  1. maths union

  2. unit

  3. united

  4. university

  5. upper

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

u 3 British  
/ juː /

noun

  1. the 21st letter and fifth vowel of the modern English alphabet

  2. any of several speech sounds represented by this letter, in English as in mute, cut, hurt, sure, pull, or minus

    1. something shaped like a U

    2. ( in combination )

      a U-bolt

      a U-turn

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

U 4 British  
/ uː /

noun

  1. a Burmese title of respect for men, equivalent to Mr

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of U2

First recorded in 1840–45

Origin of U3

First recorded in 1950–55; u(pper class)

Origin of U4

First recorded in 1930–35; from Burmese ʔú, roughly “Mister, Uncle,” used for senior men and monks

Origin of u.6

From the German word und

Origin of U.8

From the German word und

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Only 10,000 U visas become available each year, and many more applicants qualify.

From The Wall Street Journal • Apr. 22, 2026

Earlier this month, a federal grand jury in Boston indicted 10 Indian nationals for allegedly staging convenience-store holdups in Massachusetts and elsewhere to secure U visas.

From The Wall Street Journal • Apr. 21, 2026

"Even though the material itself isn't magnetic, the existence of chiral phonons gives us these magnetic levers to pull on," said Rikard Bodin, doctoral candidate at the U and co-author of the paper.

From Science Daily • Apr. 19, 2026

"We saw a few U turns in the wake of Trump's original announcement last night," says Richard Meade, editor-in-chief of Lloyd's list.

From BBC • Apr. 13, 2026

A heavy, sad feeling settles over me as I walk around the U and turn into the hallway where all the offices are.

From "Amari and the Night Brothers" by B.B. Alston