c.1340, "to take possession of," also "to take up space or time, employ (someone)," from O.Fr. occuper,
from L. occupare
"take over, seize, possess, occupy," from ob
"over" + intensive form of capere
"to grasp, seize" (see capable
). During 16c.-17c. a euphemism for "have sexual intercourse with," which caused it to fall from polite usage.
"A captaine? Gods light these villaines wil make the word as odious as the word occupy, which was an excellent good worde before it was il sorted." [Doll Tearsheet in "2 Henry IV"]