Feature of stag - and also hen party - all naked dancing (7)
I believe the answer is:
antlers
I'm afraid I can't explain this answer.
Can you help me to learn more?
(Other definitions for antlers that I've seen before include "Bony outgrowths on head of male deer" , "Stag's crowning glory" , "Head branches of 18" , "Reindeer outgrowth" , "Branched horns" .)