sideline
n.the line that marks the side of a sports field. It also refers to a job or activity you do in addition to your main work.
n.the boundary line extending along the side of a playing field; by extension, a secondary occupation or interest pursued alongside a primary career.
“The coach stood on the sideline shouting instructions.”
“She works as a lawyer but has a profitable sideline selling handmade jewelry online.”
“While the athlete was forced to watch from the sideline due to injury, he began developing a business sideline in sports commentary that eventually became his full-time profession.”
Often used in the plural ('the sidelines') when referring to the area just outside the field of play.
“Fellow new signing Bruno Guimaraes was hardly missed after being sidelined by an injury suffered in last weekend’s Community Shield win over Manchester City.”
“Baleba, who joined Brighton from Lille in 2023, is currently sidelined with an ankle injury he picked up during their pre-season training camp in Austria.”
From side + line.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.