Banishment sees major part of bigotry abandoned by millions (9)

I believe the answer is:
ostracism
'banishment' is the definition.
(ostracism is a kind of banishment)
'major part of bigotry abandoned by millions' is the wordplay.
I cannot really understand how this works, but
'part' could be 'os' (os is a kind of part) and 'os' is located in the answer.
'bigotry' could be 'racism' (I've seen this in another clue) and 'racism' is found within the answer.
A single letter 't' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'sees' is the link.
Can you help me to learn more?
(Other definitions for ostracism that I've seen before include "Shunning" , "transferring to Coventry?" , "cold shoulder" , "Refusal to associate with, exclusion from society" , "Boycott" .)
