The Collaborative International Dictionary of English v.0.48:

Polysyndeton \Pol`y*syn"de*ton\, n. [NL., from Gr. poly`s many +
   ? bound together, fr. ? to bind together; ? with + ? to
   bind.] (Rhet.)
   A figure by which the conjunction is often repeated, as in
   the sentence, "We have ships and men and money and stores."
   Opposed to asyndeton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

polysyndeton
    n 1: using several conjunctions in close succession, especially
         where some might be omitted (as in `he ran and jumped and
         laughed for joy')