1. not actively participating in something
Professional
Social
be kept on the sidelines
To be 'on the sidelines' is an expression that comes from people involved in sports. Players who are watching the game but not participating at that time are 'on the sidelines'. To be 'on the sidelines' therefore means to be a spectator in something but not have any power to effect change or influence the situation. "She remained on the sidelines while her friends received their results." "Their mother watched from the sidelines as her children were taken away."