Abbreviations U (reference Oxford English dictionary)

U.K.	United Kingdom
ult.	ultimately
Univ.	university
unkn.	unknown
Unnat.	unnatural
Unoffic.	unofficial
unstr.	unstressed
Urin.	urinary
U.S.	United States
U.S.A.F.	United States Air Force
U.S.S.R.	Union of Soviet Socialist Republics
usu.	usually
Utilit.	utilitarian

ABBREVIATIONS - A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | Y | Z |