sideline
noun
°The boundaries of a playing field.
"The coach stood on the sidelines and bellowed commands at the team."
°The outside or perimeter of any activity.
"She installed the whole fixture while he simply watched from the sidelines."
verb
°To place on the sidelines; to bench or to keep someone out of play.
"The coach sidelined the player until he regained his strength."
°To remove or keep out of circulation.
"The illness sidelined him for weeks."