Triangular bracket of brick or stone (6)
I believe the answer is:
corbel
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">triangular bracket of brick or stone</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 corbel that I've seen before include "Weight-supporting projection" , "Amount (of money) expended" , "Triangular bracket of brick or stone" , "Truss" , "Supporting projection from wall" .)