Plumper > define

(n.) One who or that which, plumps or swells out something else; hence, something carried in the mouth to distend the cheeks.
(n.) A downright, unqualified lie.
(n.) A vote given to one candidate only, when two or more are to be elected, thus giving him the advantage over the others. A person who gives his vote thus is said to plump or to plump his vote.
(n.) A voter who plumps his vote.

by Webster's Revised Unabridged Dictionary