Beam over a doorway (6)
I believe the answer is:
lintel
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">beam over a doorway</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 lintel that I've seen before include "It's found above the door" , "Horizontal timber support" , "Support across doorway" , "Horizontal beam over a door or window" , "Part of door or window frame" .)