The DICT Protocol, described in RFC 2229 is a TCP transaction based
query/response protocol that allows a client to access dictionary
definitions from a set of natural language dictionary databases. While
RFC 2229 is a finished document, we plan to clarify and enhance the
protocol definition as we gain more experience with large dictionary
database servers. By default, the DICT protocol uses TCP port 2628. 

WWW: http://www.dict.org/