1630s, "a cutting off (mentally), abstraction," from French précision (16c.) and directly from Latin praecisionem (nominative praecisio) "a cutting off," noun of action from past participle stem of praecidere "to cut off, shorten," from prae "before" (see pre-) + -cidere, combining form of caedere "to cut" (from PIE root *kae-id- "to strike"). Meaning "preciseness" is from 1740.
