1.nounA period of play in which members of a visiting baseball team attempt to hit a baseball pitched by the opposing home team until three players are called out, followed by a similar attempt by members of the home baseball team against the visiting team's pitching. There are nine or more innings in a regulation baseball game.
"It is a baseball tradition to sing "Take Me Out To the Ball Game" during the seventh inning stretch."
2.nounA similar period of play.
"We batted around in our half of the inning."
3.nounA player (or team)'s turn at the table to make shots until ended by a miss or a foul.
4.nounA chance or opportunity to perform some deed or act.
"We are in just the second inning of our quest to enter this new market."