knife vs shiv

knife and shiv both are nouns.

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

As nouns, shiv is a hyponym of knife; that is, shiv is a word with a more specific, narrower meaning than knife:

Other hyponyms of knife include bayonet, dagger, sticker, khukuri, machete, matchet, panga, trench knife, yataghan, kindjal, seax.

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

knife (verb)	shiv (verb)
use a knife on