Bellerophonic adjective1 •Of or relating to Bellerophon, a hero of Greek mythology, who was killed on the instructions of a letter given to him to deliver by the jealous Proteus.This event is counterbalanced by Astolfo's encounter with the Amazons, which also constitutes an explicitly Bellerophonic anecdote. — 1988 formsmore Bellerophonic · most Bellerophonic