Playwright O'Neill (6)
I believe the answer is:
eugene
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">playwright o'neill</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(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" .)