compulsory

adjective | \ kəm-ˈpəl-sə-rē \ | com·pul·so·ry
  1. : required or compelled by law : mandatory, obligatory compulsory arbitration compulsory insurance; specifically : required to be brought or asserted in a pleading because of having arisen from the transaction or occurrence that is the subject of litigation a compulsory counterclaim compulsory reconvention — compare elective, permissive : required to be brought or asserted in a pleading because of having arisen from the transaction or occurrence that is the subject of litigation a compulsory counterclaim compulsory reconvention — compare elective, permissive

  1. : using compulsion : compelling compulsory measures