Install
late Middle English (in install (sense 2)): from medieval Latin installare, from in- ‘into’ + stallum ‘place, stall’. install (sense 1) dates from the mid 19th century.
wiktionary
From Middle English installen, from Old French installer, from Medieval Latin installō(“to install, put in place, establish”), from in- + stallum(“stall”), from Frankish *stall(“stall, position, place”), from Proto-Germanic *stallaz(“place, position”), from Proto-Indo-European *stelǝ-, *stAlǝn-, *stAlǝm-(“stem, trunk”). Cognate with Old High German stal(“location, stall”), Old English steall(“position, stall”), Old English onstellan(“to institute, create, originate, establish, give the example of”), Middle High German anstalt(“institute”), German anstellen(“to conduct, employ”), German einstellen(“to set, adjust, position”), Dutch aanstellen(“to appoint, commission, institute”), Dutch instellen(“to set up, establish”). More at in, stall.
etymonline
install (v.)
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]
