Animal with large hood (4)
I believe the answer is:
cowl
'hood' is the definition.
(synonyms)
'animal with large' is the wordplay.
'animal' becomes 'cow' (cow is a kind of animal).
'with' means one lot of letters go next to another.
'large' becomes 'l'.
'cow'+'l'='COWL'
(Other definitions for cowl that I've seen before include "Monk's hood or chimney covering" , "Loose hood" , "Dried fruit" , "Monk's hood - chimney cover" , "Hood for monk or chimney" .)