cylinder vs barrel

cylinder and barrel both are nouns.

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

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

cylinder: a surface generated by rotating a parallel line around a fixed line
barrel: a bulging cylindrical shape; hollow with flat ends

Other hyponyms of cylinder include brake drum, drum, shank, shank, shank, stem, stalactite, stalagmite, drum, pipe, tube.

cylinder (noun)	barrel (noun)
a cylindrical container for oxygen or compressed air	a cylindrical container that holds liquids
a chamber within which piston moves	a tube through which a bullet travels when a gun is fired
a surface generated by rotating a parallel line around a fixed line	any of various units of capacity
a solid bounded by a cylindrical surface and two parallel planes (the bases)	the quantity that a barrel (of any size) will hold
	a bulging cylindrical shape; hollow with flat ends

cylinder (verb)	barrel (verb)
	put in barrels