a person who wagers money on the outcome of games or sporting events
"The local news reported that a notorious gambler was arrested for placing illegal bets on last night's championship game."
someone who risks loss or injury in the hope of gain or excitement
"The young gambler rolled his dice again, ignoring the sharp sting on his thumb as he chased another big win."
One who plays at a game of chance, who gambles.
"The nervous gambler checked his wallet before stepping into the casino to try his luck on the slot machines."