Better English head (4)
I believe the answer is:
cape
'head' is the definition.
(thesaurus)
'better english' is the wordplay.
'better' becomes 'cap' (I've seen this before**).
'english' becomes 'e' (abbreviation).
'cap'+'e'='CAPE'
(Other definitions for cape that I've seen before include "Wrath perhaps" , "Batman has one" , "Outer garment" , "Sleeveless overgarment" , "Horn or Good Hope - cloak" .)