Other forms: installed, installing, installs
To install something is to put it in place and get it working. A plumber installs a boiler, you install an app on your phone, an electrician installs the sockets before the plaster goes on.
The noun is installation, and it covers both the job and the finished thing — a heating installation, and in a gallery an art installation built into the room itself. Software brought a whole family with it: installer, reinstall, uninstall, a fresh install. The second meaning is ceremonial: you install a bishop, a chancellor, a president of the society, and there is a formal occasion behind the word every time. There is a relaxed third use with a reflexive pronoun — he installed himself in the best chair and stayed there all evening. British English allows the one-L spelling instal, but installed, installing and installation always take two.
1verbinstallTo put equipment or software in place and make it ready to use.
“They installed a new boiler in a single morning.”
2verbofficialTo place someone formally in an official position.
“She was installed as chancellor in a ceremony at the cathedral.”
3verbsettleTo settle yourself or someone else comfortably in a place.
“He installed himself by the fire with the paper.”
Also accepted in games: set up
Install came through Old French from Medieval Latin īnstallō, 'to put in place', built on in- and stallum, 'a stall'. A stall was a fixed place, a stand, a seat, so to install a man was to put him in his seat and leave him there. Boilers and software arrived centuries later and kept the idea exactly: put the thing where it belongs, and it stays.
Proto-Indo-European
*stel-
Proto-Germanic
*stallaz — place, position
Frankish
*stall — stall, position, place
Medieval Latin
īnstallō — to install, put in place, establish
Old French
installer
Middle English
installen
English, today
install
Built from
From Middle English installen, from Old French installer, from Medieval Latin īnstallō (“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 stel-, 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.
Etymology from Wiktionary, CC BY-SA