hearing vs rehearing

hearing and rehearing both are nouns.

Word	Noun	Adjective	Verb	Adverb
hearing	Yes	Yes	No	No
rehearing	Yes	No	No	No

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

Other hyponyms of hearing include auscultation, relistening.

hearing (noun)	rehearing (noun)
the act of hearing attentively	the act of hearing again
(law) a proceeding (usually by a court) where evidence is taken for the purpose of determining an issue of fact and reaching a decision based on that evidence
the ability to hear; the auditory faculty
a session (of a committee or grand jury) in which witnesses are called and testimony is taken
the range within which a voice can be heard
an opportunity to state your case and be heard

hearing (adjective)	rehearing (adjective)
able to perceive sound