Australian cockroach vs roach

Australian cockroach and roach both are nouns.

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

As nouns, roach is a hypernym of Australian cockroach; that is, roach is a word with a broader meaning than Australian cockroach:

Other hypernyms of Australian cockroach include cockroach.

Australian cockroach (noun)	roach (noun)
widely distributed in warm countries	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

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