tun vs cask

tun and cask both are nouns.

Word	Noun	Adjective	Verb	Adverb
tun	Yes	No	No	No
cask	Yes	No	No	No

As nouns, cask is a hypernym of tun; that is, cask is a word with a broader meaning than tun:

tun: a large cask especially one holding a volume equivalent to 2 butts or 252 gals
cask: a cylindrical container that holds liquids

Other hypernyms of tun include barrel.

tun (noun)	cask (noun)
a large cask especially one holding a volume equivalent to 2 butts or 252 gals	a cylindrical container that holds liquids
	the quantity a cask will hold