penalty vs requital

penalty and requital both are nouns.

Word	Noun	Adjective	Verb	Adverb
penalty	Yes	No	No	No
requital	Yes	No	No	No

As nouns, requital is a hyponym of penalty; that is, requital is a word with a more specific, narrower meaning than penalty:

Other hyponyms of penalty include retribution, forfeit, forfeiture, amercement, fine, mulct.

penalty (noun)	requital (noun)
the act of punishing, or the infliction of a penalty	an act of requiting; returning in kind
the disadvantage or painful consequences of an action or condition	a justly deserved penalty
(games) a handicap or disadvantage that is imposed on a competitor (or a team) for an infraction of the rules of the game
a payment required for not fulfilling a contract