gambler

Concise Oxford English Dictionary © 2008 Oxford University Press:
gamble/ˈɡambl/

▶verb

• 1 play games of chance for money; bet.

  ■ bet (a sum of money).

• 2 take risky action in the hope of a desired result.

▶noun

• 1 an act of gambling.

• 2 a risky undertaking or enterprise.

– derivatives
gambler noun.

– origin C18: from obs. gamel ‘play games’, or from the verb game1.