dry run vs rehearsal

dry run and rehearsal both are nouns.

Word	Noun	Adjective	Verb	Adverb
dry run	Yes	No	No	No
rehearsal	Yes	No	No	No

As nouns, dry run and rehearsal are synonyms defined as:

dry run and rehearsal: a practice session in preparation for a public performance (as of a play or speech or concert)

dry run (noun)	rehearsal (noun)
a practice session in preparation for a public performance (as of a play or speech or concert)	(psychology) a form of practice; repetition of information (silently or aloud) in order to keep it in short-term memory
	a practice session in preparation for a public performance (as of a play or speech or concert)