drill 1 
(drĭl)
(drĭl)n.
1.
a. An implement with cutting edges or a pointed end for boring holes in hard materials, usually by a rotating abrasion or repeated blows; a bit.
b. The hand-operated or hand-powered holder for this implement.
c. A loud, harsh noise made by or as if by a powered tool of this kind.
2.
a. Disciplined, repetitious exercise as a means of teaching and perfecting a skill or procedure.
b. A task or exercise for teaching a skill or procedure by repetition: conducted an air-raid drill; a drill for learning the multiplication tables.
3. The training of soldiers in marching and the manual of arms.
4. Any of various marine gastropod mollusks, chiefly of the genus Urosalpinx, that bore holes into the shells of bivalve mollusks. U. cinera is destructive to oysters.
v. drilled, drill·ing, drills
v.tr.
1.
a. To make a hole in (a hard material) with a drill: a bit for drilling masonry.
b. To make (a hole) with or as if with a drill: drills holes in trees with its chisellike bill.
2. To strike or hit sharply: The batter drilled a single through the infield.
3.
a. To instruct thoroughly by repetition in a skill or procedure: drill pupils in grammar.
b. To infuse knowledge of or skill in by repetitious instruction: drilled the correct spellings into the students' heads. See Synonyms at teach.
4. To train (soldiers) in marching and the manual of arms.
v.intr.
Phrasal Verb: 1. To make a hole with or as if with a drill.
2. To perform a training exercise.
drill down
To view data or other information at a more detailed level: business software that allows users to drill down from annual to monthly sales figures.
[Obsolete Dutch dril, from drillen, to bore, from Middle Dutch drillen; see terə-1 in the Appendix of Indo-European roots.]
driller n.