sideline

sideline [sahyd-lahyn] Word Origin 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.

verb (used with object), side·lined, side·lin·ing.

6. 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.

Origin of sideline An Americanism dating back to 1685–95; side1 + line1 British Dictionary definitions for side-lining sideline 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

verb (tr)

4. to prevent (a player) from taking part in a game
5. to prevent (a person) from pursuing a particular activity, operation, career, etc

Word Origin and History for side-lining sideline n.

also side-line, “line on the side of a fish,” 1768; “lines marking the limits of playing area” (on a football field, etc.), 1862, from side (adj.) + line (q.v.). Meaning “course of business aside from one’s regular occupation” is from 1890. Railway sense is from 1890. The figurative sense of “position removed from active participation” is attested from 1934 (from the railway sense or from sports, because players who are not in the game stand along the sidelines). The verb meaning “put out of play” is from 1945. Related: Sidelined; sidelining.