a person who supports a proposal etc in a formal meeting so that it can be discussed 〔正式会议上对某项提议的〕附议者，赞成者 → proposer
Examples from the Corpus
seconder• A nomination is made on a prescribed nomination form, signed by the candidate, proposer and seconder.• When obtaining signatures to the nomination paper the candidate must obtain the signatures of the proposer and seconder first. 4.• Ken was ably assisted by seconder Royal Robbins, who has probably drilled more bolts than anyone else.• Elections Only corporate members may participate in elections, either as candidate, proposer, seconder or voter.• The seconder, who helped push the resolution through, was the mayor of London, Adam Beck.