tax-increase vs increase

tax-increase and increase both are nouns.

Word	Noun	Adjective	Verb	Adverb
tax-increase	Yes	No	No	No
increase	Yes	No	Yes	No

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

Other hypernyms of tax-increase include increment.

tax-increase (noun)	increase (noun)
the amount by which taxes are increased	the act of increasing something
	the amount by which something increases
	a change resulting in an increase
	a process of becoming larger or longer or more numerous or more important
	a quantity that is added

tax-increase (verb)	increase (verb)
	become bigger or greater in amount
	make bigger or more