Beam fixed at one end (10)
I believe the answer is:
cantilever
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">beam fixed at one end</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 cantilever that I've seen before include "support at one end" , "bridge design" , "Projecting mass" , "Beam supported at only one end" , "Projecting beam fixed at one end" .)