The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

   2. A dependent; one under the protection of another.
      [1913 Webster]

            I do think they are your friends and clients,
            And fearful to disturb you.           --B. Jonson.
      [1913 Webster]

   3. (Law) One who consults a legal adviser, or submits his
      cause to his management.
      [1913 Webster]

WordNet (r) 3.0 (2006):

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

The Free On-line Dictionary of Computing (19 January 2023):

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)