also instal, formerly also enstall, early 15c., "place in (ecclesiastical) office by seating in an official stall," from Old French installer (14c.) or directly from Medieval Latin installare, from Latin in- "in" (from PIE root *en "in") + Medieval Latin stallum "stall," from a Germanic source (compare Old High German stal "standing place;" see stall (n.1)). Related: Installed; installing.
In the church of England the installation of a canon or prebendary of a cathedral consists in solemnly inducting him into his stall in the choir and his place in the chapter. [Century Dictionary]