Etymology
From Middle English enviroun (“round about in a circle or ring; all around”) [and other forms], from Anglo-Norman enviroun, environ [and other forms], and Middle French enviroun, environ [and other forms], from Old French environ (“around, surrounding; about, approximately, roughly”) (modern French environ), from en- (prefix meaning ‘in; into’) + viron (“circuit; circumference, compass; country round about”) (though first attested later) (from virer (“to bear, turn, veer”) (either from Latin gȳrō (“to turn in a circle, rotate; to circle, revolve around”) (ultimately from Proto-Indo-European *gew- (“to bend, curve; an arch, vault”)), or from Latin vibrō (“to hurl, launch; shake; to tremble, vibrate”) (ultimately from Proto-Indo-European *weyb-, *weyp- (“to shake; to tremble; to sway, swing;
Definitions & examples from Wiktionary (CC BY-SA 3.0).