sideline
side-line
noun
An additional activity or job done alongside one's main employment.
"Running a small business was his profitable sideline."
noun
A line marking the side boundary of a playing field in sports.
"The referee ruled the ball crossed the sideline."
verb
To prevent a player from participating, often due to injury or other reasons.
"An injury sidelined the key player for weeks."
Thesaurus
Synonyms: pursuit, avocation, by-line, hobby, spare-time activity, out of bounds