The Collaborative International Dictionary of English v.0.48:

Seawan \Sea"wan\, Seawant \Sea"want\, n.
   The name used by the Algonquin Indians for the shell beads
   which passed among the Indians as money.
   [1913 Webster]

   Note: Seawan was of two kinds; wampum, white, and
         suckanhock, black or purple, -- the former having
         half the value of the latter. Many writers, however,
         use the terms seawan and wampum indiscriminately.
         --Bartlett.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Wampum \Wam"pum\, n. [North American Indian wampum, wompam, from
   the Mass. w['o]mpi, Del. w[=a]pe, white.]
   Beads made of shells, used by the North American Indians as
   money, and also wrought into belts, etc., as an ornament.
   [1913 Webster]

         Round his waist his belt of wampum.      --Longfellow.
   [1913 Webster]

         Girded with his wampum braid.            --Whittier.
   [1913 Webster]

   Note: These beads were of two kinds, one white, and the other
         black or dark purple. The term wampum is properly
         applied only to the white; the dark purple ones are
         called suckanhock. See Seawan. "It [wampum] consisted
         of cylindrical pieces of the shells of testaceous
         fishes, a quarter of an inch long, and in diameter less
         than a pipestem, drilled . . . so as to be strung upon
         a thread. The beads of a white color, rated at half the
         value of the black or violet, passed each as the
         equivalent of a farthing in transactions between the
         natives and the planters." --Palfrey.
         [1913 Webster]

WordNet (r) 3.0 (2006):

wampum
    n 1: informal terms for money [syn: boodle, bread,
         cabbage, clams, dinero, dough, gelt, kale,
         lettuce, lolly, lucre, loot, moolah, pelf,
         scratch, shekels, simoleons, sugar, wampum]
    2: small cylindrical beads made from polished shells and
       fashioned into strings or belts; used by certain Native
       American peoples as jewelry or currency [syn: wampum,
       peag, wampumpeag]