automatic pistol vs pistol

automatic pistol and pistol both are nouns.

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

As nouns, pistol is a hypernym of automatic pistol; that is, pistol is a word with a broader meaning than automatic pistol:

automatic pistol: a pistol that will keep firing until the ammunition is gone or the trigger is released
pistol: a firearm that is held and fired with one hand

Other hypernyms of automatic pistol include automatic firearm, automatic gun, automatic weapon, handgun, shooting iron, side arm.

automatic pistol (noun)	pistol (noun)
a pistol that will keep firing until the ammunition is gone or the trigger is released	a firearm that is held and fired with one hand