Sentence:  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 <WSD>high-roller</WSD>. 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. 
Meaning of the word marked with <WSD> tags:  One who has a lot of money and lives luxuriously.