Name on the cover of "Anna Christie" (6)
I believe the answer is:
eugene
(Other definitions for eugene that I've seen before include "Great Irish-American playwright . . . . . . O'Neill" , "fellow" , ". . . . . . Onegin (Tchaikovsky) (6)" , "Dramatist...... O'Neill wrote 'The Iceman Cometh'" , "Great American playwright . . . . . . O'Neill" .)