Source : Free On-Line Dictionary of Computing

Exterior Gateway Protocol
     
        (EGP) A protocol which distributes routing information to the
        {router}s which connect {autonomous system}s.  The term
        "{gateway}" is historical, and "router" is currently the
        preferred term.  There is also a routing protocol called {EGP}
        defined in STD 18, RFC 904.  See also {Border Gateway
        Protocol}, {Interior Gateway Protocol}.