flick knife vs flick-knife

flick knife and flick-knife both are nouns.

Word	Noun	Adjective	Verb	Adverb
flick knife	Yes	No	No	No
flick-knife	Yes	No	No	No

As nouns, flick knife and flick-knife are synonyms defined as:

flick knife and flick-knife: a pocketknife with a blade that springs open at the press of a button

Other synonyms of flick knife include switchblade, switchblade knife.

flick knife (noun)	flick-knife (noun)
a pocketknife with a blade that springs open at the press of a button	a pocketknife with a blade that springs open at the press of a button