Sean , author of the stage play The Plough and the Stars (6)
I believe the answer is:
ocasey
(Other definitions for ocasey that I've seen before include "Sean ..., author of 'The Plough and the Stars'" , "Sean .'..... wrote ` `The Shadow of a Gunman' ' (1'5)" , "Sean . . . . . . wrote ''The Plough and the Stars'' (1 '5)" , "Sean . . . . . . wrote 'Juno and the Paycock'" , "one connected with The Abbey" .)