switchblade vs switchblade knife

switchblade and switchblade knife both are nouns.

Word	Noun	Adjective	Verb	Adverb
switchblade	Yes	No	No	No
switchblade knife	Yes	No	No	No

As nouns, switchblade and switchblade knife are synonyms defined as:

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

Other synonyms of switchblade include flick-knife, flick knife.

switchblade (noun)	switchblade 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