ETYM Cf. French manuel, Late Lat. manuale. Related to Manual.
A small handbook.

ETYM Old Eng. manuel, French manuel, Latin manualis, from manus hand; prob. akin to as. mund hand, protection, Old High Germ. munt, German mündel a ward, vormund guardian, Icel. mund hand. Related to Emancipate, Legerdemain, Maintain, Manage, Manner, Manure, Mound a hill.
1. Of or relating to the hands.
2. Requiring human effort.
Doing or requiring physical work.

In music, any of the keyboards of a multikeyboard instrument played by the hands. A harpsichord often has two manuals and an organ has up to four (great organ, swell organ, choir organ, and solo organ). The pedal keyboard (pedalboard) of the organ is not a manual.