pruning knife vs knife

pruning knife and knife both are nouns.

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

As nouns, knife is a hypernym of pruning knife; that is, knife is a word with a broader meaning than pruning knife:

pruning knife: a knife with a curved or hooked blade
knife: edge tool used as a cutting instrument; has a pointed blade with a sharp edge and a handle

pruning knife (noun)	knife (noun)
a knife with a curved or hooked blade	edge tool used as a cutting instrument; has a pointed blade with a sharp edge and a handle
	a weapon with a handle and blade with a sharp point
	any long thin projection that is transient

pruning knife (verb)	knife (verb)
	use a knife on