hush money vs payoff

hush money and payoff both are nouns.

Word	Noun	Adjective	Verb	Adverb
hush money	Yes	No	No	No
payoff	Yes	No	No	No

As nouns, payoff is a hypernym of hush money; that is, payoff is a word with a broader meaning than hush money:

hush money: a bribe paid to someone to insure that something is kept secret
payoff: payment made to a person in a position of trust to corrupt his judgment

Other hypernyms of hush money include bribe.

hush money (noun)	payoff (noun)
a bribe paid to someone to insure that something is kept secret	a recompense for worthy acts or retribution for wrongdoing
	the final payment of a debt
	payment made to a person in a position of trust to corrupt his judgment
	the income or profit arising from such transactions as the sale of land or other property