This is the official designation of the president or chairman of certain legislative bodies, particularly of the house, of representatives in the congress of the United States, of one or both branches of several of the state legislatures and of the two houses of the British parliament. The term “speaker,” as used in reference to either of the houses of parliament signifies the functionary acting as chairman. In the commons his duties are to put questions, to preserve order, and to see that the privileges of the house are not infringed; and, in the event of the numbers being even on a division, he has the privilege of giving the casting vote. The speaker of the lords is the lord chancellor or the lord keeper of the great seal of England, or, if he be absent the lords may choose their own speaker. The duties of the speaker of the lords are principally confined to putting questions, and the lord chancellor has no more to do with preserving order than any other peer: Brown.
SPEAKER
TheLaw.com Law Dictionary & Black's Law Dictionary 2nd Ed.