In hold 'em poker: Describes a hand's relationship to a flop when conditions exist where not only is the hand likely the strongest, but can also easily improve to the nuts (aka best hand possible).
Hero holds pocket KQ of hearts. Flop comes Kc 4h 7h. This gives hero a flush draw and top pair. Even against an opponent with pocket AA or a made set (unlikely), he or she has enough outs to be considered the best hand. "He hit gin on that flop!"