Sweat

word type: verb

To observe or follow the progress and goings-on in a poker game.
To anxiously endure the outcome of a close poker situation.

E.g.

"I spent all day sweating Gus Hansen in the WSOP, and then he donked off his chips like usual."

"So I got this guy in a clamp and then the turn brings the ten of hearts and suddenly I gotta sweat 13 outs."