sideline

(noun) a line that marks the side boundary of a playing field. Synonyms: out of bounds.

(noun) an auxiliary line of merchandise.

(noun) an auxiliary activity. Synonyms: avocation, by-line, hobby, pursuit, spare-time activity.

(verb) remove from the center of activity or attention; place into an inferior position. Example: "The outspoken cabinet member was sidelined by the president."