imbue vs riddle

imbue is not a noun while riddle is a noun.

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

As verbs, imbue and riddle are synonyms defined as:

Other synonyms of imbue include diffuse, interpenetrate, penetrate, permeate, pervade.

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

imbue (verb)	riddle (verb)
suffuse with color	explain a riddle
fill, soak, or imbue totally	set a difficult problem or riddle
spread or diffuse through	speak in riddles
	pierce with many holes
	separate with a riddle, as grain from chaff
	spread or diffuse through