barrel vs butt

barrel and butt both are nouns.

Word	Noun	Adjective	Verb	Adverb
barrel	Yes	No	Yes	No
butt	Yes	No	Yes	No

As nouns, butt is a hyponym of barrel; that is, butt is a word with a more specific, narrower meaning than barrel:

barrel: a cylindrical container that holds liquids
butt: a large cask (especially one holding a volume equivalent to 2 hogsheads or 126 gallons)

Other hyponyms of barrel include beer barrel, beer keg, hogshead, keg, pickle barrel, shook, tun, wine barrel, wine cask.

barrel (noun)	butt (noun)
a cylindrical container that holds liquids	thick end of the handle
a tube through which a bullet travels when a gun is fired	the small unused part of something (especially the end of a cigarette that is left after smoking)
any of various units of capacity	a large cask (especially one holding a volume equivalent to 2 hogsheads or 126 gallons)
the quantity that a barrel (of any size) will hold	sports equipment consisting of an object set up for a marksman or archer to aim at
a bulging cylindrical shape; hollow with flat ends	finely ground tobacco wrapped in paper; for smoking
	a joint made by fastening ends together without overlapping
	the fleshy part of the human body that you sit on
	a victim of ridicule or pranks
	the part of a plant from which the roots spring or the part of a stalk or trunk nearest the roots

barrel (verb)	butt (verb)
put in barrels	to strike, thrust or shove against
	place end to end without overlapping
	lie adjacent to another or share a boundary