riddle vs perforate

riddle is a noun but perforate is not a noun.

Word	Noun	Adjective	Verb	Adverb
riddle	Yes	No	Yes	No
perforate	No	Yes	Yes	No

As verbs, perforate is a hypernym of riddle; that is, perforate is a word with a broader meaning than riddle:

Other hypernyms of riddle include penetrate.

riddle (noun)	perforate (noun)
a coarse sieve (as for gravel)
a difficult problem

riddle (adjective)	perforate (adjective)
	having a hole cut through

riddle (verb)	perforate (verb)
explain a riddle	make a hole into or between, as for ease of separation
set a difficult problem or riddle	pass into or through, often by overcoming resistance
speak in riddles
pierce with many holes
separate with a riddle, as grain from chaff
spread or diffuse through