Avatar
from Sanskrit avatāra ‘descent’, from ava ‘down’ + tar- ‘to cross’.
wiktionary
Attested 1784, [1] borrowed from Hindustani अवतार / اوتار (avtār), from Sanskrit अवतार(avatāra, “descent of a deity from a heaven”), a compound of अव(ava, “off, away, down”) and the vṛddhi-stem of the root √तॄ(√tṝ, “to cross”).
In computing use, saw some use in 1980s videos games – 1985 online role-playing game Habitat by Lucasfilm Games (today LucasArts), by Chip Morningstar and Randy Farmer, [2] later versions of the Ultima series (following religious use in 1985 Ultima IV: Quest of the Avatar), and 1989 pen and paper role-playing game Shadowrun. Popularized by the 1992 novel Snow Crash by Neal Stephenson. [1]
etymonline
avatar (n.)
1784, "descent of a Hindu deity to earth in an incarnate or tangible form," from Sanskrit avatarana "descent" (of a deity to the earth in incarnate form), from ava- "off, down" (from PIE root *au- (2) "off, away") + base of tarati "(he) crosses over," from PIE root *tere- (2) "cross over, pass through, overcome."
Meaning "concrete embodiment of something abstract" is from 1815. In computer use, it seems to trace to the novel "Snowcrash" (1992) by Neal Stephenson.