punky vs gnat

punky and gnat both are nouns.

Word	Noun	Adjective	Verb	Adverb
punky	Yes	No	No	No
gnat	Yes	No	No	No

As nouns, gnat is a hypernym of punky; that is, gnat is a word with a broader meaning than punky:

punky: minute two-winged insect that sucks the blood of mammals and birds and other insects
gnat: any of various small biting flies: midges; biting midges; black flies; sand flies

punky (noun)	gnat (noun)
minute two-winged insect that sucks the blood of mammals and birds and other insects	any of various small biting flies: midges; biting midges; black flies; sand flies
	(British usage) mosquito