The d in 'advance' is a lie — but a very old one. The word entered English in the thirteenth century from Old French avancier, meaning 'to move forward', which descended from Vulgar Latin *abantiare and ultimately Late Latin abante ('from before'), combining ab ('from') and ante ('before'). There was no d anywhere in the chain. But English speakers, familiar with Latin prefixes, assumed the initial a- must be ad- ('towards') and helpfully inserted a d. The French never made this correction, which is why they still write avancer. Despite its accidental spelling, the word's meaning has been remarkably stable: physical forward movement, figurative progress, and — from the fifteenth century — money given ahead of time. The same Latin root ante also produced 'advantage' (originally avantage) and, via Italian, 'avant-garde' — the guard that goes before.