"precise, rigorous, accurate," 1530s, from Latin exactus "precise, accurate, highly finished," past-participle adjective from exigere "demand, require, enforce," literally "to drive or force out," also "to finish, measure," from ex "out" (see ex-) + agere "to set in motion, drive, drive forward; to do, perform" (from PIE root *ag- "to drive, draw out or forth, move").
exact (v.)
"to force or compel to be paid or yielded," mid-15c., from Latin exactus, past participle of exigere "require, enforce, demand, collect (money);" see exact (adj.). Older in English than the adjective and retaining the literal sense of the Latin source. Related: Exacted; exacting.
hit the exact center of the target
an exact copy
an exact mind
ex officio
ex parte
ex post facto
exacerbate
exacerbation
exact
exacta
exacting
exaction
exactitude
exactly