1610s (n.), 1640s (v.), from Du. dril, drille "a hole, instrument for boring holes," from drillen "to bore (a hole), turn around, whirl," from P.Gmc. *threljanan. Sense of "to instruct in military exercise" is 1620s (also in Du. drillen and in the Dan. and Ger. cognates), probably from the notion of troops "turning" in maneuvers. Extended sense of "the agreed-upon procedure" is from 1940. Related: Drilled; drilling.
"small furrow," 1727; also "machine for sowing seeds" (1731), from obsolete drill "rill, trickling stream" (1640s), of unknown origin, perhaps connected to drill (1).
"W. African baboon species," 1644, perhaps from a native word.