speaker

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. One who speaks.
2. n. A spokesperson.
3. n. One who delivers a public speech.
4. n. The presiding officer of a legislative assembly.
5. n. A loudspeaker.

Century Dictionary and Cyclopedia

1. n. One who speaks or utters words; one who talks or converses; one who mates a speech or an address; specifically, one who engages in or practises public speaking.
2. n. A proclaimer; a publisher.
3. n. The title of the presiding officer in the British House of Commons, in the House of Representatives in the Congress of the United States, in the lower houses of State legislatures in the United States, and in British colonial legislatures; also of the Lord Chancellor of Great Britain as presiding officer of the House of Lords. The Speaker of the House of Commons is elected in each Parliament from its members, with the royal concurrence, generally without regard to politics, and may preside in successive Parliaments of opposite political character. His powers (which have been much diminished in the course of time) are limited to the preservation of order and the regulation of debate under the rules of the House, the use of the casting-vote in case of an equal division, and speaking in general committee. The Speaker in the House of Representatives (as also in the State legislatures) is usually a leader of the party having a majority of the members, and has, in addition to the powers of the British Speaker, the power of appointing all committees, and the right, as a member, of participating in general debate after calling another member to the chair, and of voting on all questions—rights exercised, however, only on important occasions. He is thus in a position to control the course of legislation to an important extent, and the office is consequently regarded as of great power and influence.
4. n. A title, and hence a general name, for a book containing selections for practice in declamation, as at school.

Wiktionary

1. n. One who speaks.
2. n. Loudspeaker.
3. n. politics The chair or presiding officer of certain legislative bodies, such as the U.K. House of Commons or the U.S. House of Representatives.
4. n. One who makes a speech to an audience.
5. n. US A book containing passages of text for use in speeches.
6. n. linguistics The producer of a given utterance, whether actually spoken or not.

GNU Webster's 1913

1. n. One who speaks.
2. n. One who utters or pronounces a discourse; usually, one who utters a speech in public.
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
4. n. United States A book of selections for declamation.

WordNet 3.0

1. n. electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance
2. n. someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)
3. n. the presiding officer of a deliberative assembly