u

1 of 5

noun

ˈyü 

plural u's or us ˈyüz 

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

ˈyü 

: characteristic of the upper classes

U

4 of 5

abbreviation (2)

1

unsatisfactory

2

uracil

U

5 of 5

symbol

uranium

Examples of u in a Sentence

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

Phrases Containing u

• double-u

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