supplementary supplementary /ˌsəpləˈmɛntəˌriː/

adjective

1. () Functioning in a supporting capacity  ( subsidiary , auxiliary , supplemental , supplementary )
   functioning in a supporting capacity
    The main library and its auxiliary branches
   the main library and its auxiliary branches
   
2. Added to complete or make up a deficiency  ( supplemental , supplementary )
   added to complete or make up a deficiency
    Produced supplementary volumes
   produced supplementary volumes