sideline

American  

[sahyd-lahyn] / ˈsaɪdˌlaɪn /

noun

1. a line at the side of something.

2. a business or activity pursued in addition to one's primary business; a second occupation.

3. an additional or auxiliary line of goods.

   a grocery store with a sideline of household furnishings.

4. Sports.

   1. either of the two lines defining the side boundaries of a field or court.

   2. sidelines, the area immediately beyond either sideline, where the substitute players sit.

5. sidelines, the position or point of view taken by a person who observes an activity or situation but does not directly participate in it.

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verb (used with object)

sidelined, sidelining

1. to render incapable of participation, especially in anything involving vigorous, physical action, as a sport.

   An injury to his throwing arm sidelined the quarterback for two weeks.

sideline British  

/ ˈsaɪdˌlaɪn /

noun

1. sport a line that marks the side boundary of a playing area

2. a subsidiary interest or source of income

3. an auxiliary business activity or line of merchandise

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verb

1. to prevent (a player) from taking part in a game

2. to prevent (a person) from pursuing a particular activity, operation, career, etc

Etymology

Origin of sideline

An Americanism dating back to 1685–95; side ¹ + line ¹

Example Sentences

Leda, rather graciously I think, doesn’t mind staying on the sideline of the story, even though everyone seems to forget that Eddie was her stepfather, too.

From The Wall Street Journal • May 29, 2026

The head coach shouting harsh critiques from the sideline, the assistant coach there to put his arm around you when you made it, crestfallen and ashamed, back to the bench.

From Los Angeles Times • May 28, 2026

He is not a demonstrative individual, in news conferences or on the sideline.

From BBC • May 3, 2026

Later in the game, Rays sideline reporter Ryan Bass visited the family at their seats and presented both kids with baseballs.

From Los Angeles Times • Apr. 29, 2026

From the outset, he ran back and forth on his sideline, barking at his players in a hoarse bellow: “Man on! Man on! Drop it! Drop it! Turn! Turn! Turn!”

From "Outcasts United: An American Town, a Refugee Team, and One Woman's Quest to Make a Difference" by Warren St. John