live one

A lively, or interesting or annoying or peculiar or uncontrollable etc etc person
Also someone or something likely to win in a game, race etc.

"Looks like we've got ourselves a live one"
"I've bet on a real live one"

by sevenhn November 3, 2005

In poker, a bad player at the table. Good players rely on live ones to play too many hands, and thus give away their money by making mistakes.

Almost anyone would be a live one in the high stakes poker games in Vegas since they would get outplayed by the top professionals.

by Stephen Bennett April 18, 2006