Jason jilted her (5)
I believe the answer is:
medea
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">jason jilted her</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 medea that I've seen before include "Greek sorceress" , "Tragedy by Euripedes" , "Tragic heroine" , "Greek princess who helped Jason get the Golden Fleece" , "Jason's wife who murdered their children" .)