genitourinary vs GU

genitourinary is not a noun while GU is a noun.

Word	Noun	Adjective	Verb	Adverb
genitourinary	No	Yes	No	No
GU	Yes	Yes	No	No

As adjectives, genitourinary and GU are synonyms defined as:

genitourinary and GU: of or related to the genital and urinary organs or their functions

genitourinary (noun)	GU (noun)
	the largest and southernmost island in the Marianas which is administered as a territory of the United States; it was ceded by Spain to the United States in 1898

genitourinary (adjective)	GU (adjective)
of or related to the genital and urinary organs or their functions	of or related to the genital and urinary organs or their functions