cockroach vs roach

cockroach and roach both are nouns.

Word	Noun	Adjective	Verb	Adverb
cockroach	Yes	No	No	No
roach	Yes	No	Yes	No

As nouns, cockroach and roach are synonyms defined as:

cockroach and roach: any of numerous chiefly nocturnal insects; some are domestic pests

cockroach (noun)	roach (noun)
any of numerous chiefly nocturnal insects; some are domestic pests	any of numerous chiefly nocturnal insects; some are domestic pests
	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

cockroach (verb)	roach (verb)
	cut the mane off (a horse)
	comb (hair) into a roach