It's an English language term. It means entry into the baseball game. Also in cricket. It refers to each of the parts in which the game is divided ( nine ) that correspond to the batting turns of each team. Lasts until 3 outs are completed for each team.
INNING anglilicism by entry into a baseball or cricket game. 2 . Figuratively years, life : he's had a good innings : it has had a good life; has lived his good years.