Tragic king (4)
I believe the answer is:
lear
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tragic king</span>' is the definition.<br/ ><span class="explanation-format__explanation">(Shakespeare's King Lear)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for lear that I've seen before include "Playful king and writer of nonsense verse" , "Shakespear's king" , "The Bard's foolish king" , "Edward, writer of nonsense verse" , "See 27 Across" .)