stupefy vs riddle

stupefy is not a noun while riddle is a noun.

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

As verbs, riddle is a hyponym of stupefy; that is, riddle is a word with a more specific, narrower meaning than stupefy:

Other hyponyms of stupefy include mix up, stump, elude, escape.

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

stupefy (verb)	riddle (verb)
make senseless or dizzy by or as if by a blow	explain a riddle
be a mystery or bewildering to	set a difficult problem or riddle
make dull or stupid or muddle with drunkenness or infatuation	speak in riddles
	pierce with many holes
	separate with a riddle, as grain from chaff
	spread or diffuse through