Buck's rack (7)
I believe the answer is:
antlers
'buck's rack' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for antlers that I've seen before include "Head branches of 18" , "Bony outgrowths on head of male deer" , "Deer horns" , "Stag's crowning glory" , "Branched horns" .)