Sidelines vs Sidelined - What's the difference?

As a noun sidelines

is plural of lang=en The lines marking the edges.

past tense of sideline.

(head)

The lines marking the edges.

The area or areas next to but outside a playing area.

The coaches watched from the sidelines , remembering their days of glory but only able to offer advice.

(head)

(sideline)

A line at the side of something, as in "the yellow sideline of the road".

(sports) A line defining the side boundary of a playing field.

(usually, in the plural) The area outside the playing field beyond each sideline.

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 .

Something that is additional or extra or that exists around the edges or margins of a main item.

She started the business as a sideline to her regular work and it ended up becoming the greater source of income.

Soup need not be just a sideline to a meal; if you like, it can be the main course.

(sidelin)

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.