Vanish
Middle English: shortening of Old French e(s)vaniss-, lengthened stem of e(s)vanir, from Latin evanescere ‘die away’.
wiktionary
Aphetic for obsolete evanish, from Middle English vanyshen, evaneschen, from Old French esvanir, esvaniss- (modern French évanouir), from Vulgar Latin *exvanire(“to vanish, disappear, to fade out”), from Latin evanescere, from vanus(“empty”). Doublet of evanesce.
etymonline
vanish (v.)
"disappear quickly," c. 1300, from shortened form of esvaniss-, stem of Old French esvanir "disappear; cause to disappear," from Vulgar Latin *exvanire, from Latin evanescere "disappear, pass away, die out," from ex "out" (see ex-) + vanescere "vanish," inchoative verb from vanus "empty, void," from PIE *wano-, suffixed form of root *eue- "to leave, abandon, give out." Related: Vanished; vanishing; vanishingly. Vanishing point in perspective drawing is recorded from 1797.
