New name for hair (4)
I believe the answer is:
mane
'hair' is the definition.
(I have seen 'Long hair ' mean 'mane' so perhaps 'hair' could also mean 'mane')
'new name' is the wordplay.
'new' indicates an anagram.
'name' anagrammed gives 'MANE'.
'for' is the link.
(Other definitions for mane that I've seen before include "Animal neck-hair" , "Long thick hair" , "Hair (of lion)" , "(Lion's) hair on neck" , "Long shaggy hair" .)