Meaning of CONFERENCE in English

CONFERENCE

[noun] - an event, sometimes lasting a few days, at which there are a group of talks on a particular subject, or a meeting in which esp. business matters are discussed formallyShe spoke at a conference that I went to on AIDS. [C]That's the room where they hold conferences. [C]I'm attending a conference the whole of next week. [C]Caroline O'Neill isn't available at present. She's in conference (= is in a meeting). [U]Should I book the conference room for the meeting?

Cambridge English vocab.      Кембриджский английский словарь.