"the operation or practice of fixing colors in solution in textiles, hides, hair, etc.," late 14c., verbal noun from dye (v.).
late 14c., rehersaille, "restatement, repetition of the words of another; account, narration," from rehearse + -al (2), or from Old French rehearsal "a repeating." Sense in theater and music, "act or process of studying by practice or preparatory exercise, a meeting of musical or dramatic performers for practice and study together" is from 1570s. A play being in rehearsal is from 1709. Pre-wedding rehearsal dinner attested by 1953.