The first portion of an inning in baseball in which the visiting team take their at-bats.
In baseball, each inning is divided into two halves. The first half of any inning is referred to as the top of the inning, with the home team playing defense and the visiting team batting. The term originated due to the line score of a baseball game, in which the runs, hits, errors and sometimes additional stats are listed in a two rows, with the visiting team's numbers listed on the top row.