six-shooter vs revolver

six-shooter and revolver both are nouns.

Word	Noun	Adjective	Verb	Adverb
six-shooter	Yes	No	No	No
revolver	Yes	No	No	No

As nouns, six-shooter and revolver are synonyms defined as:

six-shooter and revolver: a pistol with a revolving cylinder (usually having six chambers for bullets)

Other synonyms of six-shooter include six-gun.

six-shooter (noun)	revolver (noun)
a pistol with a revolving cylinder (usually having six chambers for bullets)	a pistol with a revolving cylinder (usually having six chambers for bullets)
	a door consisting of four orthogonal partitions that rotate about a central pivot; a door designed to equalize the air pressure in tall buildings