High-roller

Tom is a high-roller.

Source: tatoeba (6678133)

The "Baron" bowed. This was a new complication, but it was all in the day's work. Of course, the whole thing was plain enough. Fatty Welch was "working" some swell guys who thought he was a real high-roller. Maybe he was going to pull off some kind of a job that very evening. Perhaps this big chap in the swagger flannels was one of the gang. Barney was thinking hard. Well, he'd take the tip and play the hand out.

Source: wiktionary

He was a bigger net yield than any two or three girls because a satisfied woman was far more generous than a depleted john. And frequently, Rocco owed a high-roller a favor and the girl came back with nothing.

Source: wiktionary