semiautomatic vs semiautomatic pistol

semiautomatic and semiautomatic pistol both are nouns.

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

As nouns, semiautomatic and semiautomatic pistol are synonyms defined as:

semiautomatic and semiautomatic pistol: a pistol that is a semiautomatic firearm capable of loading and firing continuously

semiautomatic (noun)	semiautomatic pistol (noun)
a pistol that is a semiautomatic firearm capable of loading and firing continuously	a pistol that is a semiautomatic firearm capable of loading and firing continuously

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