Window fitter (7)
I believe the answer is:
glazier
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">window fitter</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 glazier that I've seen before include "Window fitter" , "Person who cuts flat glass to size" , "Craftsman" , "Glass fitter" , "Glassworker" .)