an intermission between the first and second half of a game, especially a football game. Also used attributively, as the halftime entertainment

Second half. Line posted after the first half is over, to bet on which team will have a higher score on the second half. It usually has a total as well. Overtime is also a part of the halftime.

The break between the second and third quarters. Last 12 minutes during the regular season and 20 minutes during the Super Bowl. A time for coaches to prepare second half strategy.

The interval between halves, usually 15 minutes.