1. Someone who serves in a subordinate capacity or plays a secondary role
   "The vice president often felt like a second banana in the administration";
   - second fiddle
    
2. A performer who acts as stooge to a comedian
   "The second banana set up the jokes perfectly for his comedy partner"

Derived forms: second bananas

Type of: foot soldier, performer, performing artist, subordinate, subsidiary, underling, understrapper [informal]

Encyclopedia: Second banana