Save Type Surname (from occupation & from location) Usage Dutch Pronounced Pron. /koːi̯/ [key·simplify] Other Forms FormsKooi, Kooy Meaning & History From Dutch kooi meaning "cage", often referring to a pen or duck decoy (a plot of land with a pond set aside to lure in ducks). Occupational name for someone who raised or hunted ducks, or who made cages.