Source : Webster's Revised Unabridged Dictionary (1913)

Plump \Plump\ (pl[u^]mp), a. [Compar. {Plumper} (-[~e]r);
   superl. {Plumpest}.] [OE. plomp rude, clumsy; akin to D.
   plomp, G., Dan., & Sw. plump; probably of imitative origin.
   Cf. {Plump}, adv.]
   Well rounded or filled out; full; fleshy; fat; as, a plump
   baby; plump cheeks. --Shak.

         The god of wine did his plump clusters bring. --T.
                                                  Carew.

Plumper \Plump"er\, n.
   1. One who, or that which, plumps or swells out something
      else; hence, something carried in the mouth to distend the
      cheeks.

   2. (English Elections) 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.

   3. A voter who plumps his vote. [Eng.]

   4. A downright, unqualified lie. [Colloq. or Low]