Triangular part of a house (5)
I believe the answer is:
gable
'triangular part of a house' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for gable that I've seen before include "Triangular upper part of a wall under a roof" , "See 18" , "Filmstar at the side of the house?" , "Roof structure" , "Triangular brickwork" .)