to engage the attention or energies of (somebody)
to fill up (a portion of space or time)
to take or maintain possession of (e.g. land or a building)
to reside in or use (a building) as an owner or tenant
to hold (a particular job or position)
occupier noun
[Middle English occupien to take possession of, occupy, via French from Latin occupare to seize, take over, from oc- + capere to take]