The Collaborative International Dictionary of English v.0.48:

rubber band \rub"ber band"\, n.
   A closed loop of rubber usually having a thin rectangular
   cross-section; also called elastic band; -- it varies in
   length from the circumference of a finger to several inches,
   and is usually used to hold several objects together
   temporarily, by the tension exerted when the band is
   stretched and fitted around the objects to be held; as, to
   hold a pack of cards together with a rubber band.
   [PJC]

The Collaborative International Dictionary of English v.0.48:

elastic band \e*las"tic band"\, n.
   Same as rubber band.
   [PJC]

WordNet (r) 3.0 (2006):

elastic band
    n 1: a narrow band of elastic rubber used to hold things (such
         as papers) together [syn: rubber band, elastic band,
         elastic]