Triangular bracket of brick or stone (6)
I believe the answer is:
corbel
'triangular bracket of brick or stone' is the definition.
(I've seen this before)
This is all the clue.
(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" .)