Playwright O'Neill (6)
I believe the answer is:
eugene
'playwright o'neill' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for eugene that I've seen before include "opera, but only first half" , "fellow" , "Great Irish-American playwright . . . . . . O'Neill" , "- - Onedin" , "Great American playwright . . . . . . O'Neill" .)