injure vs handicap

injure is not a noun while handicap is a noun.

Word	Noun	Adjective	Verb	Adverb
injure	No	No	Yes	No
handicap	Yes	No	Yes	No

As verbs, handicap is a hyponym of injure; that is, handicap is a word with a more specific, narrower meaning than injure:

injure (noun)	handicap (noun)
	advantage given to a competitor to equalize chances of winning
	something immaterial that interferes with or delays action or progress
	the condition of being unable to perform as a consequence of physical or mental unfitness

injure (verb)	handicap (verb)
cause injuries or bodily harm to	injure permanently
cause damage or affect negatively	put at a disadvantage
hurt the feelings of	attempt to forecast the winner (especially in a horse race) and assign odds for or against a contestant