noun

• (mining) A person or machine responsible for managing a mineshaft cage.
• (dated, informal) A basketball player, from the time when games were played in a wire mesh enclosure.
  "In 1946, Athletic Director Chandler reliquished his position as head basketball coach at the school to one of his most proficient former players, Julius Rubin. Despite the fact that Rubin had never coached a cager squad before, he became a well-liked leader for the players assembled to start the 1946-1947 season."
• (cycling, derogatory) A person who drives an automobile, particularly for commuting.
  "Motorcycles can go where cars can’t. Obscure places, remote singletrack trails, off-road tracks too narrow for four wheels – on a bike, you can literally go anywhere and access places no car ever would feeling like an explorer and discovering wild spots off-limits for cagers."