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1.
ucg
U.C.G.(under cover girlfriend) a girl or bitch you keep on the side if you main girl wont fuck.
Fam my main line almost got me with the UCG
by odd twix bar March 03, 2010
 
2.
UCG
URBAN COW GIRL a young girl obsessed with horses she may also often be seen all over your man.
"damn, UCG be all up on that black stallion jaqueese."

by sprouse September 04, 2006