drill (n.1)

"tool for making holes in hard substances," 1610s, from Dutch dril, drille "a hole, instrument for boring holes," from drillen "to bore (a hole), turn around, whirl," from PIE root *tere- (1) "to rub, turn."

"small furrow; trench or channel in which seeds are deposited," 1727; also "machine for sowing seeds" (1731), from obsolete drill "rill, trickling stream" (1640s), which is of unknown origin; perhaps connected to drill (n.1).

also drilling, kind of coarse, stout 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) "having three threads, triple-twilled," from tri- (see tri-) + licium "thread," a word of unknown etymology. So called in reference to the method of weaving it.

"West African baboon species," 1640s, perhaps from a native word (compare mandrill).

"pierce or make a hole in with a drill or similar tool," c. 1600 (implied in drilling), from Dutch drillen "to bore (a hole), turn around, whirl," from Proto-Germanic *thr- (source also of Middle High German drillen "to turn, round off, bore," Old English þyrel "hole"), from PIE root *tere- (1) "to rub, turn," with derivatives referring to twisting, boring, and drilling. Related: Drilled, drilling. Compare thrill, the native English form of the word. Drill-press "drilling machine for boring holes in metal" is by 1850.

"to instruct in military exercise," 1620s (a sense also found in Dutch drillen and the Danish and German cognates), probably from drill (v.1) on the notion of troops "turning" in maneuvers. Related: Drilled, drilling.

As a noun, "act of training soldiers in military tactics," 1630s; the extended sense of "the agreed-upon procedure" is by 1940. Drill-sergeant "non-commissioned officer who instructs soldiers in their duties and trains them in military movements" is by 1760. Drill-master "one who gives practical instructions in military tactics" is by 1766.