plunger (n.)

• adventurer
• bettor
• boneshaker
• cardsharp
• cardsharper
• diver
• frogman
• gambler
• gunslinger
• jumper
• operator
• player
• punter
• scalper
• sharp
• sharper
• sharpie
• speculator
• sport
• sportsman
• stag
• tipster
• tout
• venturer
• wagerer