gambler

noun

person who gambles, either professionally or recreationally

Wiktionary

noun

Etymology: Etymology tree English gamble Proto-Indo-European *-yósder. Proto-Italic *-āzijos Latin -āriusnom. Latin -āriusbor. Proto-Germanic *-ārijaz Proto-West Germanic *-ārī Old English -ere Middle English -ere English -er English gambler From gamble + -er.

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