A sudden, violent recoil of disgust.
A sudden, violent recoil of disgust — being pulled or drawn away from something repellent.
The most violent and physical/recoiling member: it adds suddenness and the bodily image of being torn away from the offending thing (its literal root is “pulling away”). Typically acute and reactive rather than settled — “a wave of revulsion.” More visceral than the principled repugnance and the steady base of disgust; not the enduring, deliberate hatred of loathing or abhorrence.
1540s, originally a medical term (counter-irritation), from Latin revulsionem “a tearing away,” from revellere “to pull away” (re- “away” + vellere “to tear, pull”). The literal root is “a pulling away.”
Entered English as a medical/physical term (a “pulling away”); the emotional sense — “sudden reaction of disgust” — is attested by 1816, growing out of the physical image. The medical sense still survives. No reliable recent-generation shift.