English Etymology From horse + player. Noun horseplayer (plural horseplayers) (gambling) A person who bets on horse races. 2007 July 1, Vincent M. Mallozzi, “Handicapping the Handicappers”, in New York Times:Trailing a field of talented horseplayers that day, he made a few shrewd picks to move ahead, then held on down the stretch to earn $50,000.Wikiwand - on Seamless Wikipedia browsing. On steroids.