Excessive labour (7)
I believe the answer is:
travail
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">excessive labour</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for travail that I've seen before include "Labour, toil" , "Exertion, elbow grease" , "Painful or laborious effort, like childbirth" , "Use of physical or mental energy; excessive labour..." , "Hard labour" .)