Gambler

n. better, wagerer; card-player, gamester; one who plays games of chance

The term gambling has had many different meanings depending on the cultural and historical context in which it is used. Currently, in Western societies, it has an economic definition, referring to "wagering money or something of material value on an event with an uncertain outcome with the primary intent of winning additional money and/or material goods". Typically, the outcome of the wager is evident within a short period of time.
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Gambling Vox populi An activity in which a person wagers against another person–eg, friend, acquaintance, bookmaker or 'bookie', or [more]Gambler - Community and Resources

Noun
1. a person who wagers money on the outcome of games or sporting events
(hypernym) person, individual, someone, somebody, mortal, human, soul
(hyponym) ex-gambler
(derivation) gamble
2. someone who risks loss or injury in the hope of gain or excitement
(synonym) risk taker
(hypernym) adventurer, venturer
(derivation) gamble, chance, risk, hazard, take chances, adventure, run a risk, take a chance

(n.)
One who gambles.