sticker vs knife

sticker and knife both are nouns.

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

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

sticker (noun)	knife (noun)
a short knife with a pointed blade used for piercing or stabbing	edge tool used as a cutting instrument; has a pointed blade with a sharp edge and a handle
an adhesive label	a weapon with a handle and blade with a sharp point
a particularly difficult or baffling question or problem	any long thin projection that is transient
a small sharp-pointed tip resembling a spike on a stem or leaf

sticker (verb)	knife (verb)
	use a knife on