1an activity done in addition to one’s main job, especially to earn extra income: [as modifier]:a sideline career as a stand-up comic
an auxiliary line of goods or trade:electronic handbooks are a lucrative sideline for the firm
2either of the two lines bounding the longer sides of a football field, basketball court, or similar:Gascoigne celebrated his goal by sprinting to the sidelines
(the sidelines) the area immediately outside such lines as a place for non-players, substitutes, or spectators:a referee collapsed during a match as his son watched from the sidelines
(the sidelines) a position where one is observing a situation rather than directly involved in it:we are not just watching from the sidelines, we are rolling our sleeves up and getting involved
verb
[with object]
cause (a player) to be unable to play in a team or game:an ankle injury has sidelined him for two weeks
remove from the centre of activity or attention; place in a less influential position:backbench MPs have been sidelined and excluded from decision-making
sideline in other Oxford dictionaries
Definition of sideline in the US English dictionary
