oc·cu·py / ˈäkyəˌpī/ • v. (-pies, -pied) [tr.] 1. reside or have one's place of business in (a building): the apartment she occupies in Manhattan. ∎  fill or take up (a space or time): two long windows occupied almost the whole wall. ∎  be situated in or at (a place or position in a system or hierarchy): on the corporate ladder, they occupy the lowest rungs. ∎  hold (a position or job).2. (often be occupied with/in) fill or preoccupy (the mind or thoughts): her mind was occupied with alarming questions. ∎  keep (someone) busy and active: Sarah occupied herself taking the coffee cups over to the sink | [as adj.] (occupied) tasks that kept her occupied for the remainder of the afternoon. 3. take control of (a place, esp. a country) by military conquest or settlement: Syria was occupied by France under a League of Nations mandate. ∎  enter, take control of, and stay in (a building) illegally and often forcibly, esp. as a form of protest: the workers occupied the factory.DERIVATIVES: oc·cu·pi·er / -ˌpīər/ n.ORIGIN: Middle English: formed irregularly from Old French occuper, from Latin occupare ‘seize.’ A now obsolete vulgar sense ‘have sexual relations with’ seems to have led to the general avoidance of the word in the 17th and most of the 18th cent.

occupy †take possession of; have in one's possession; take up, use up; employ, engage XIV; †lay out, invest XVI. — AN. *occupier for (O)F. occuper — L. occupāre seize, f. OC- + cap- of capere take, seize.
So occupant XVI, occupier, occupation XIV.