Gather around extremely elegant bit of leg (7)
I believe the answer is:
fetlock
'bit of leg' is the definition.
(joint in a quadruped's leg)
'gather around extremely elegant' is the wordplay.
'gather' becomes 'flock' (flocking is a kind of gathering**).
'around' means one lot of letters goes inside another.
'extremely' suggests removing the centre.
'elegant' with its middle removed is 'et'.
'flock' placed around 'et' is 'FETLOCK'.
(Other definitions for fetlock that I've seen before include "Horse's leg joint" , "beastly joint" , "Joint just above a horse's hoof -- to fleck (anag)" , "Part of a charger" , "Projection above a horse's hoof" .)