Source : Webster's Revised Unabridged Dictionary (1913)

Speaker \Speak"er\, n.
   1. One who speaks. Specifically:
      (a) One who utters or pronounces a discourse; usually, one
          who utters a speech in public; as, the man is a good
          speaker, or a bad speaker.
      (b) One who is the mouthpiece of others; especially, one
          who presides over, or speaks for, a delibrative
          assembly, preserving order and regulating the debates;
          as, the Speaker of the House of Commons, originally,
          the mouthpiece of the House to address the king; the
          Speaker of a House of Representatives.

   2. A book of selections for declamation. [U. S.]

Source : WordNet®

speaker
     n 1: someone who expresses in language; someone who talks
          (especially someone who delivers a public speech or
          someone especially garrulous); "the speaker at
          commencement"; "an utterer of useful maxims" [syn: {talker},
           {utterer}, {verbalizer}, {verbaliser}]
     2: electro-acoustic transducer that converts electrical signals
        into sounds loud enough to be heard at a distance [syn: {loudspeaker},
         {speaker unit}, {loudspeaker system}, {speaker system}]
     3: the presiding officer of a deliberative assembly; "the
        leader of the majority party is the Speaker of the House
        of Representatives"

Source : Free On-Line Dictionary of Computing

speaker
     
        1.  {loudspeaker}.
     
        2. The person who is (assumed to be) talking.
     
        (1996-12-01)