capital gains tax vs tax

capital gains tax and tax both are nouns.

Word	Noun	Adjective	Verb	Adverb
capital gains tax	Yes	No	No	No
tax	Yes	No	Yes	No

As nouns, tax is a hypernym of capital gains tax; that is, tax is a word with a broader meaning than capital gains tax:

capital gains tax: a tax on capital gains
tax: charge against a citizen's person or property or activity for the support of government

Other hypernyms of capital gains tax include revenue enhancement, taxation.

capital gains tax (noun)	tax (noun)
a tax on capital gains	charge against a citizen's person or property or activity for the support of government

capital gains tax (verb)	tax (verb)
	make a charge against or accuse
	use to the limit
	levy a tax on
	set or determine the amount of (a payment such as a fine)