Main definitions of u in English

: u1U2U3U4U5

u1

Physics
  • Denoting quantum states or wave functions which change sign on inversion through the origin.

    The opposite of g

  • [in combination] (in units of measurement) micro- (10−6)

    ‘direct read-out of concentration in ug or mg/l’

Pronunciation:

u

/juː/

Main definitions of u in English

: u1U2U3U4U5

U2

(also u)

noun

  • 1The twenty-first letter of the alphabet.

    not in service, unavailable for use, not in use, out of action, unserviceable
    View synonyms
    1. 1.1Denoting the next after T in a set of items, categories, etc.
  • 2A shape like that of a capital U, especially a cross section.

    [in combination] ‘U-shaped glaciated valleys’

Pronunciation:

U

/juː/

Main definitions of u in English

: u1U2U3U4U5

U3

  • 1(in names of sports clubs) United.

    ‘Oxford U’
  • 2British Universal (denoting films classified as suitable without restriction).

  • 3Uruguay (international vehicle registration).

  • 4informal You.

    ‘what will u do next?’

  • The chemical element uranium.

Pronunciation:

U

/juː/

Main definitions of u in English

: u1U2U3U4U5

U4

adjective

British
informal
  • (of language or social behaviour) characteristic of or appropriate to the upper social classes.

    ‘U manners’
    upper-class, aristocratic, upmarket, home counties
    View synonyms

Origin

1950s: abbreviation of upper class; coined in 1954 by Alan S. C. Ross, professor of linguistics, the term was popularized by its use in Nancy Mitford's Noblesse Oblige (1956).

Pronunciation:

U

/juː/

Main definitions of u in English

: u1U2U3U4U5

U5

noun

  • A Burmese title of respect before a man's name, equivalent to Mr.

    ‘U Thien San’

Pronunciation:

U

/uː/