From Longman Dictionary of Contemporary Englishproposerpro‧pos‧er /prəˈpəʊzə $ -ˈpoʊzər/ noun [countable] formal a person who formally suggests a plan, course of action etc at a meeting for people to vote on → seconder
Examples from the Corpus
proposer• Elections Only corporate members may participate in elections, either as candidate, proposer, seconder or voter.• A nomination is made on a prescribed nomination form, signed by the candidate, proposer and seconder.• Two of the female proposers of motions are married with four children each.• But, when the times comes, his proposers look as if they will have an incontestable piece of evidence.• In support of this it can be asked, if the proposers of a merger can not demonstrate such benefits then who can?• The names of the proposer and seconder will not be published and will remain confidential to the scrutineers.• A proposed right is a claim which the proposer would like the society to enforce.From Longman Business Dictionaryproposerpro‧pos‧er /prəˈpəʊzə-ˈpoʊzər/ noun [countable]1someone who makes a proposal at a formal meeting2INSURANCE someone who is buying an INSURANCE POLICY