Definition of "U"
U1
/juː/
U2
/juː/
noun
adjective
not generally comparable, comparative Uer, superlative Uest
(comparable, chiefly Britain, dated) Abbreviation of upper class (“characteristic of the upper classes, particularly in the use of language”).
(not comparable) Abbreviation of united.
(not comparable) Abbreviation of upper.
(not comparable, education, espionage) Usually in parentheses: abbreviation of unclassified.
preposition
(sports) Abbreviation of under.
(stenoscript) Abbreviation of under, prefix under-.
U3
/juː/