Proposer is not a minor, oddly (9)
I believe the answer is:
nominator
'proposer' is the definition.
(I have seen 'The proposer' mean 'nominator' so perhaps 'proposer' could also mean 'nominator')
'not a minor oddly' is the wordplay.
'oddly' indicates an anagram.
'not'+'a'+'minor'='notaminor'
'notaminor' is an anagram of 'NOMINATOR'.
'is' is the link.
(Other definitions for nominator that I've seen before include "someone who makes proposal" , "One proposing candidate" , "The proposer" , "One who proposes" , "One who puts forward a candidate for election" .)