fixing vs restitution

fixing and restitution both are nouns.

Word	Noun	Adjective	Verb	Adverb
fixing	Yes	No	No	No
restitution	Yes	No	No	No

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

fixing (noun)	restitution (noun)
the act of putting something in working order again	getting something back again
the sterilization of an animal	the act of restoring something to its original state
(histology) the preservation and hardening of a tissue sample to retain as nearly as possible the same relations they had in the living body	a sum of money paid in compensation for loss or injury
restraint that attaches to something or holds something in place