roach vs R-2

roach and R-2 both are nouns.

Word	Noun	Adjective	Verb	Adverb
roach	Yes	No	Yes	No
R-2	Yes	No	No	No

As nouns, roach and R-2 are synonyms defined as:

Other synonyms of roach include circle, forget me drug, Mexican valium, roofy, rope, rophy.

roach (noun)	R-2 (noun)
any of numerous chiefly nocturnal insects; some are domestic pests	street names for flunitrazepam
European freshwater food fish having a greenish back
the butt of a marijuana cigarette
street names for flunitrazepam
a roll of hair brushed back from the forehead

roach (verb)	R-2 (verb)
cut the mane off (a horse)
comb (hair) into a roach