1550s, "state of occupying beforehand," from Latin praeoccupationem (nominative praeoccupatio) "a seizing beforehand, anticipation," noun of action from past participle stem of praeoccupare, from prae- "before" (see pre-) + occupare "seize" (see occupy). Meaning "mental absorption" is from 1854. Earlier its secondary sense was "bias, prejudice" (c.1600).