pivotal pivotal /ˈpɪvətəl/

adjective

1. Being of crucial importance  ( pivotal , polar )
   being of crucial importance
    A pivotal event
   a pivotal event
    Its pivotal location has also exposed it to periodic invasions
   Its pivotal location has also exposed it to periodic invasions
    The polar events of this study
   the polar events of this study
    A polar principal
   a polar principal