What is the meaning of Speaker?

noun

• Someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous. )
  • usage: "the speaker at commencement"; "an utterer of useful maxims"
  • synonyms: talker, utterer, verbalizer, verbaliser
• Electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance.
  • synonyms: loudspeaker, speaker unit, loudspeaker system, speaker system
• The presiding officer of a deliberative assembly.
  • usage: "the leader of the majority party is the Speaker of the House of Representatives"