sideline

Sideline refers to the boundary line along the edge of a playing field that marks the out-of-bounds area in many sports. It also denotes the adjacent area where non-playing personnel—such as coaches, substitutes, medical staff, and officials—stand or sit during a game. The sideline is typically marked by a painted line and may include a designated seating area or bench for players and staff.

In competitive sports, the sideline serves as the management and safety zone for substitutions and game-day logistics. Players who are not actively in play remain near the sideline, and access to the field is restricted beyond the line according to the rules of the sport. The term is frequently used to describe both the physical space and the group of people who operate there, especially in sports such as football and soccer.

As a verb, sideline means to remove someone from active participation in a game or activity, often temporarily, by benching or relegating them to a non-playing role. Decisions to sideline can be tactical, disciplinary, medical, or administrative, and the person may later return to play depending on circumstances.

In broader usage, sideline can describe peripheral activities or secondary goals that are not central to the main effort. The phrase on the sideline is common, and sideline reporters are journalists stationed near the action to provide live updates.