seller noun a gambler who bets on a result lower than the bookmaker’s favoured spread UK
Brian is optimistic about Arsenal’s chances and decides to be a buyer (bets higher) at £10 per point. Sally, on the other hand, is pessimistic. She is a seller (bets lower), also at £10 per point. — David Bennet, KnowYourBets, p. 108, 2001