taxation vs government income

taxation and government income both are nouns.

Word	Noun	Adjective	Verb	Adverb
taxation	Yes	No	No	No
government income	Yes	No	No	No

As nouns, government income is a hypernym of taxation; that is, government income is a word with a broader meaning than taxation:

Other hypernyms of taxation include government revenue.

taxation (noun)	government income (noun)
the imposition of taxes; the practice of the government in levying taxes on the subjects of a state	income available to the government
charge against a citizen's person or property or activity for the support of government
government income due to taxation