late 14c., from Old French registre (13c.) and directly from Medieval Latin registrum, alteration of Late Latin regesta "list, matters recorded," noun use of Latin regesta, neuter plural of regestus, past participle of regerere "to record; retort," literally "to carry back, bring back" from re- "back" (see re-) + gerere "carry, bear" (see gest).
Also borrowed in Dutch, German, Swedish, Danish. Some senses influenced by association with Latin regere "to rule, to guide, to keep straight." Meaning in printing, "exact alignment of presswork" is from 1680s. Musical sense is from 1811, "compass or range of a voice or instrument," hence "series of tones of the same quality" (produced by a voice or instrument). Sense "device by which data is automatically recorded" is 1830, from the verb; hence Cash register (1875).