sideline

/ˈsaɪdlaɪn/noun

A boundary line running along the edge of something, such as a sports field.

Example sentence

“The coach paced up and down the sideline during the match.”

The idiom 'on the sidelines' means watching without taking part. A sideline can also be a small extra business.

Related words

goalpostA standard or target that someone keeps changing unfairly, as in the phrase "move the goalposts."dugoutA low, sheltered bench area beside a sports field where coaches and substitute players sit during a match.netDescribing an amount that is left after all costs, taxes, or other deductions have been taken away.scoreboardA big display at a game or competition that shows how many points each side has.stopwatchA watch that can be started and stopped to measure exactly how much time has passed.shinguardA protective pad worn over the front of the lower leg, especially during sports.