(Can this(+) etymology be sourced?) From the Latin verb vincō. It could either be the stem of the present active participle vincēns, vincentis (“the conquering man”) or it could be the third person plural, future active indicative of vincō, vincere, vīci, victum (“they conquer”).
vincent (plural vincents)
- (historical slang) The victim or dupe in a betting game, especially bowls.
1977, Gãmini Salgãdo, The Elizabethan Underworld, Folio Society, published 2006, page 26:
- If the vincent could actually be persuaded to play a game, the professionals always won in the end, either because of their superior skill or because of such stratagems as those described by Greene [...].