Hostility from bowler (perhaps Ellison) initially (4)
I believe the answer is:
hate
'hostility' is the definition.
(thesaurus)
'bowler perhaps ellison initially' is the wordplay.
'bowler perhaps' becomes 'hat' (bowler is a kind of hat**).
'initially' suggests taking the first letters.
The initial letter of 'ellison' is 'e'.
'hat'+'e'='HATE'
'from' acts as a link.
(Other definitions for hate that I've seen before include "Despise" , "Odium" , "Abominate" , "Passion" , "Dislike intensely" .)