Definition of u
(Entry 1 of 5)
1a
: 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
Definition of u (Entry 2 of 5)
Definition of U (Entry 3 of 5)
: characteristic of the upper classes
Definition of U (Entry 4 of 5)
1
unsatisfactory
2
uracil
U
symbolDefinition of U (Entry 5 of 5)
uranium
Buying Guide
Check out the 11 best games for word lovers from our Reviews team.
Test Your Vocabulary
Name That Color
-
- Name that color:

Test your vocabulary with our 10-question quiz!
TAKE THE QUIZ
A daily challenge for crossword fanatics.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridged
Share u
Time Traveler for u
The first known use of u was before the 12th century
See more words from the same century