Other forms: averted, averting, averts
To avert a disaster is to stop it happening. The strike called off, the crash that never came.
The word is formal and belongs to news writing: avert a crisis, avert a war, avert a shutdown at the last minute. It always concerns something bad that was on its way. There is a second and quite physical sense, since to avert your eyes is to turn them away from something you do not want to see, and that phrase is nearly the only place the sense survives. The noun is aversion, which means a strong dislike.
1verbavertTo prevent something bad from happening.
“A last-minute deal averted the strike.”
2verbturnTo turn your eyes or face away.
“She averted her gaze from the screen.”
Also accepted in games: prevent
To avert is to turn away. Latin ab, away, plus vertō, to turn, so averting your eyes and averting a disaster are the same movement made at different scales.
Proto-Indo-European
*wert-
Latin
āvertō
Old French
avertir — turn, direct, avert; turn the attention, make aware
Middle English
averten
English, today
avert
Built from
From Middle English averten, adverten, from Old French avertir (“turn, direct, avert; turn the attention, make aware”), from Latin āvertō, from ab + vertō (“to turn”).
Etymology from Wiktionary, CC BY-SA