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

The 6-foot-6 Matarazzo cut an imposing figure on the sideline, and his players bought into his high-energy style immediately.

From The Wall Street Journal • Apr. 18, 2026

Asked after the game what motivated him to continue pacing the sideline, Auriemma joked, “Well, after tonight, I don’t know that I want to continue coaching.”

From The Wall Street Journal • Apr. 4, 2026

In an interview with reporters on Wednesday, the St. Louis Fed president, Alberto Musalem, said he supported the policy of sticking to the sideline for now.

From MarketWatch • Apr. 2, 2026

A well-regarded battalion commander in Yemen’s armed forces, Ashaal, then 42, worked a sideline in real estate with a partner.

From Los Angeles Times • Mar. 30, 2026

As I trotted to the sideline I kept staring at the stands, not for my parents anymore, but at Webb’s.

From "Crash" by Jerry Spinelli