Source : Webster's Revised Unabridged Dictionary (1913)

Keyboard \Key"board`\, n.
   The whole arrangement, or one range, of the keys of an organ,
   typewriter, etc.

Source : WordNet®

keyboard
     n 1: device consisting of a set of keys on a piano or organ or
          typewriter or typesetting machine or computer or the
          like
     2: holder consisting of an arrangement of hooks on which keys
        or locks can be hung

Source : Free On-Line Dictionary of Computing

keyboard
     
         A {hardware} device consisting of a number of
        mechanical buttons (keys) which the user presses to input
        characters to a computer.
     
        Keyboards were originally part of {terminals} which were
        separate {peripheral} devices that performed both input and
        output and communicated with the computer via a {serial line}.
        Today a keyboard is more likely to be connected more directly
        to the processor, allowing the processor to scan it and detect
        which key or keys are currently pressed.  Pressing a key sends
        a low-level {key code} to the keyboard input driver routine
        which translates this to one or more {characters} or special
        actions.
     
        Keyboards vary in the keys they have, most have keys to
        generate the {ASCII} {character set} as well as various
        {function keys} and special purpose keys, e.g. reset or volume
        control.
     
        (2003-07-04)