The Collaborative International Dictionary of English v.0.48:

internet \in"ter*net\ ([i^]n"t[~e]r*n[e^]t), n.
   A large network[3] of numerous computers connected through a
   number of major nodes of high-speed computers having
   high-speed communications channels between the major nodes,
   and numerous minor nodes allowing electronic communication
   among millions of computers around the world; -- usually
   referred to as the internet. It is the basis for the
   World-Wide Web.
   [PJC]