Noun

• S: (n) sideline, out of bounds (a line that marks the side boundary of a playing field)
• S: (n) sideline (an auxiliary line of merchandise)
• S: (n) avocation, by-line, hobby, pursuit, sideline, spare-time activity (an auxiliary activity)

Verb

• S: (v) sideline (remove from the center of activity or attention; place into an inferior position) "The outspoken cabinet member was sidelined by the President"