Source : Webster's Revised Unabridged Dictionary (1913)

Client \Cli"ent\, n. [L. cliens, -emtis, for cluens, one who
   hears (in relation to his protector), a client, fr. L. cluere
   to be named or called; akin to Gr. ? to hear, Skr. [,c]ry,
   and E. loud: cf. F. client. See {Loud}.]
   1. (Rom. Antiq.) A citizen who put himself under the
      protection of a man of distinction and influence, who was
      called his patron.

   2. A dependent; one under the protection of another.

            I do think they are your friends and clients, And
            fearful to disturb you.               --B. Jonson.

   3. (Law) One who consults a legal adviser, or submits his
      cause to his management.

Source : WordNet®

client
     n 1: a person who seeks the advice of a lawyer
     2: someone who pays for goods or services [syn: {customer}]
     3: (computer science) any computer that is hooked up to a
        computer network [syn: {node}, {guest}]

Source : Free On-Line Dictionary of Computing

client
     
         A computer system or process that requests a
        service of another computer system or process (a "{server}")
        using some kind of {protocol} and accepts the server's
        responses.  A client is part of a {client-server} software
        architecture.
     
        For example, a {workstation} requesting the contents of a file
        from a {file server} is a client of the file server.
     
        (1997-10-27)