Opposed to throwing a tin (4)
I believe the answer is:
'opposed to' is the definition.
(I've seen this before)
'throwing a tin' is the wordplay.
'throwing' is an anagram indicator.
'atin' anagrammed gives 'ANTI'.
(Other definitions for anti that I've seen before include "Person opposed", "(Person who is) not in favour", "Not favouring", "Naysayer", "Negative vote".)