Animal enthusiast with a large ring (7)
I believe the answer is:
buffalo
'animal' is the definition.
(I've seen this before)
'enthusiast with a large ring' is the wordplay.
'enthusiast' becomes 'buff' (I've seen this before).
'with' says to put letters next to each other.
'large' becomes 'L' (eg in clothes sizes).
'ring' becomes 'O' (letter resembling a ring).
'buff'+'a'+'l'+'o'='BUFFALO'
(Other definitions for buffalo that I've seen before include "Animal whose milk made mozzarella initially" , "Bovid animal" , "Colloquialism for the N American bison" , "Wild animals" , "NY port; --- Bill (Cody)" .)