u

1 of 5

noun

plural u's or us ˈyüz How to pronounce u (audio)
often capitalized, often attributive
1
a
: the 21st letter of the English alphabet
b
: a graphic representation of this letter
c
: a speech counterpart of orthographic u
2
: a graphic device for reproducing the letter u
3
: one designated u especially as the 21st in order or class
4
[abbreviation for unsatisfactory]
a
: a grade rating a student's work as unsatisfactory
b
: one graded or rated with a U
5
: something shaped like the letter U

u

2 of 5

abbreviation (1)

1
unit
2
unsymmetrical
3
physics up (see up entry 4 sense 5)
4
upper

U

3 of 5

adjective

: characteristic of the upper classes

U

4 of 5

abbreviation (2)

1
unsatisfactory
2
uracil

U

5 of 5

symbol

uranium

Example Sentences

Noun There are three u's in “unusual.” a word that starts with u

Word History

Etymology

Adjective

upper class

First Known Use

Noun

before the 12th century, in the meaning defined at sense 1a

Adjective

1954, in the meaning defined above

Time Traveler
The first known use of u was before the 12th century

Dictionary Entries Near u

Cite this Entry

“U.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/u. Accessed 7 Dec. 2022.

Kids Definition

u

noun
ˈyü
often capitalized
: the 21st letter of the English alphabet

Medical Definition

U

1 of 2 abbreviation
uracil

U

2 of 2 symbol
uranium

More from Merriam-Webster on u

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!


Challenging Words You Should Know

  • hedgehog reading a book
  • Often used to describe “the march of time,” what does inexorable mean?
Name That Thing

You know what it looks like… but what is it called?

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ