Available Definitions:
1) n. - One who speaks.
2) n. - 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.
3) n. - 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.
4) n. - A book of selections for declamation.