1. A line that marks the side boundary of a playing field
   "The ball went over the sideline for a throw-in"
    
2. An auxiliary activity
   "Photography was her sideline, while teaching remained her primary career";
   - avocation, by-line, hobby, pursuit, spare-time activity
    
3. An auxiliary line of merchandise
   "The store added a sideline of handmade crafts to boost sales"

1. Remove from the centre of activity or attention; place into an inferior position
   "The outspoken cabinet member was sidelined by the President"

Derived forms: sidelining, sidelines, sidelined

Type of: break, bump, business line, demote, interest, kick downstairs [informal], line, line of business, line of merchandise, line of products, pastime, product line, pursuit, relegate

Encyclopedia: Sideline