Heap of stones for terrier (5)
I believe the answer is:
cairn
I believe this clue is a double definition.
'heap of stones' is the first definition.
(I've seen this in another clue)
'for terrier' is the second definition.
(cairn terrier is a kind of terrier)
(Other definitions for cairn that I've seen before include "Stone-pile landmark" , "Variety of 10" , "Agree" , "Piled-stone marker" , "Memorial mound of stones" .)