gamester

   1. obsolete a prostitute

   One who played the game¹.

    She's impudent, my lord, and was a common gamester to the camp. (Shakespeare, All's Well That Ends Well)

   2. a gambler

   Gaming has meant gambling since the 16th century because most wagers turn on the outcome of games:

    The credit of a race-horse, a gamester, and a whore, lasteth but a short time. (Torriano, 1642)

   And in the ABC used by myself and my children:

    G was a gamester who had but ill luck. (In those innocent days, we saw no impropriety in 'U was an usher who loved little boys'.)