The runner on third base waits to start home until the batter has bunted successfully WordNet 3.0 & Open English WordNet

A play by the team at-bat where with a runner at third base, the batter puts down a sacrifice bunt with the aim of allowing the runner to score. In contrast to a suicide squeeze, the runner waits to see the trajectory of the ball before deciding whether to attempt to touch home plate. Wiktionary

The tactic of bunting the ball to help a runner at third base score. Wiktionary