ferret out vs ferret

ferret out is not a noun while ferret is a noun.

Word	Noun	Adjective	Verb	Adverb
ferret out	No	No	Yes	No
ferret	Yes	No	Yes	No

As verbs, ferret out and ferret are synonyms defined as:

ferret out and ferret: search and discover through persistent investigation

ferret out (noun)	ferret (noun)
	domesticated albino variety of the European polecat bred for hunting rats and rabbits
	musteline mammal of prairie regions of United States; nearly extinct

ferret out (verb)	ferret (verb)
search and discover through persistent investigation	search and discover through persistent investigation
	hunt with ferrets
	hound or harry relentlessly