semiautomatic vs handgun

semiautomatic and handgun both are nouns.

Word	Noun	Adjective	Verb	Adverb
semiautomatic	Yes	Yes	No	No
handgun	Yes	No	No	No

As nouns, handgun is a hypernym of semiautomatic; that is, handgun is a word with a broader meaning than semiautomatic:

semiautomatic: a pistol that is a semiautomatic firearm capable of loading and firing continuously
handgun: a firearm that is held and fired with one hand

Other hypernyms of semiautomatic include pistol, shooting iron, side arm, semiautomatic firearm.

semiautomatic (noun)	handgun (noun)
a pistol that is a semiautomatic firearm capable of loading and firing continuously	a firearm that is held and fired with one hand

semiautomatic (adjective)	handgun (adjective)
(of firearms) capable of automatic loading and firing continuously
partially automatic