A back-formation from swindler, itself borrowed from German Schwindler (swindler, cheat, fraudster), from schwindeln (to be dizzy, to swindle, to make up stories) and schwinden (to disappear, dwindle, faint) — suggesting the idea of someone who 'vanishes' with the money. Swindler entered English around 1762, reportedly brought to London by German merchants. Swindle as a verb and noun followed shortly after.