Why is the ninth month called September?
"tool for making holes," 1610s, from Dutch dril, drille "a hole, instrument for boring holes," from drillen "to bore (a hole), turn around, whirl" (see drill (v.)).
"small furrow," 1727; also "machine for sowing seeds" (1731), from obsolete drill "rill, trickling stream" (1640s), of unknown origin; perhaps connected to drill (n.1).
kind of coarse, twilled cloth, 1743, from French drill, from German drillich "heavy, coarse cotton or linen fabric," from Old High German adjective drilich "threefold," from Latin trilix (genitive trilicis) "triply twilled" (see trellis). So called in reference to the method of weaving it.
"West African baboon species," 1640s, perhaps from a native word (cf. mandrill).
c.1600 (implied in drilling), from Dutch drillen "to bore (a hole), turn around, whirl," from Proto-Germanic *threljanan (cf. Middle High German drillen "to turn, round off, bore," Old Engish þyrel "hole"), from PIE *tere- "to turn, rub" (see throw (v.)). Sense of "to instruct in military exercise" is 1620s (also in Dutch drillen and in the Danish and German cognates), probably from the notion of troops "turning" in maneuvers. Extended noun sense of "the agreed-upon procedure" is from 1940. Related: Drilled.
The way of doing something; the plan of action: Pain in the ass, but that's the drill (1940+)verb