The Collaborative International Dictionary of English v.0.48:
Drill \Drill\, n.
1. An instrument with an edged or pointed end used for making
holes in hard substances; strictly, a tool that cuts with
its end, by revolving, as in drilling metals, or by a
succession of blows, as in drilling stone; also, a drill
2. (Mil.) The act or exercise of training soldiers in the
military art, as in the manual of arms, in the execution
of evolutions, and the like; hence, diligent and strict
instruction and exercise in the rudiments and methods of
any business; a kind or method of military exercises; as,
infantry drill; battalion drill; artillery drill.
3. Any exercise, physical or mental, enforced with regularity
and by constant repetition; as, a severe drill in Latin
4. (Zool.) A marine gastropod, of several species, which
kills oysters and other bivalves by drilling holes through
the shell. The most destructive kind is Urosalpinx
Bow drill, Breast drill. See under Bow, Breast.
Cotter drill, or Traverse drill, a machine tool for
Diamond drill. See under Diamond.
Drill jig. See under Jig.
Drill pin, the pin in a lock which enters the hollow stem
of the key.
Drill sergeant (Mil.), a noncommissioned officer whose
office it is to instruct soldiers as to their duties, and
to train them to military exercises and evolutions.
Vertical drill, a drill press.