injury vs accident

injury and accident both are nouns.

Word	Noun	Adjective	Verb	Adverb
injury	Yes	No	No	No
accident	Yes	No	No	No

As nouns, accident is a hypernym of injury; that is, accident is a word with a broader meaning than injury:

injury (noun)	accident (noun)
wrongdoing that violates another's rights and is unjustly inflicted	anything that happens suddenly or by chance without an apparent cause
an act that causes someone or something to receive physical damage	an unfortunate mishap; especially one causing damage or injury
an accident that results in physical damage or hurt
a casualty to military personnel resulting from combat
any physical damage to the body caused by violence or accident or fracture etc.; the condition of an injury