knife vs weapon system

knife and weapon system both are nouns.

Word	Noun	Adjective	Verb	Adverb
knife	Yes	No	Yes	No
weapon system	Yes	No	No	No

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

knife: a weapon with a handle and blade with a sharp point
weapon system: any instrument or instrumentality used in fighting or hunting

Other hypernyms of knife include arm, weapon.

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

knife (verb)	weapon system (verb)
use a knife on