One who plays at a game of chance, who gambles. / One who takes significant risks.

plural of gambler

Synonym of Monte Carlo fallacy

syphilis

(UK, idiomatic) A driver of a road vehicle who accelerates when the traffic lights change from green to amber (instead of stopping, as required by law), gambling that no vehicle will cross his or her path; a driver who starts off when the traffic lights show red and amber together, but not yet green.

plural of amber gambler