flamethrower vs weapon

flamethrower and weapon both are nouns.

Word	Noun	Adjective	Verb	Adverb
flamethrower	Yes	No	No	No
weapon	Yes	No	No	No

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

Other hypernyms of flamethrower include arm, weapon system.

flamethrower (noun)	weapon (noun)
a weapon that squirts ignited fuel for several yards	any instrument or instrumentality used in fighting or hunting
	a means of persuading or arguing