1590s, "a turning away from;" 1650s in the figurative sense of "mental attitude of repugnance or opposition," from Middle French aversion (16c.) and directly from Latin aversionem (nominative aversio), noun of action from past participle stem of aversus "turned away, backwards, behind, hostile," itself past participle of avertere "to turn away" (see avert). Aversion therapy in psychology is from 1946.
