a person who announces (= lets others know about, usually in public) some news or items in a programme;
a person who reads news or introduces people, programmes, etc. on radio or TV;
an anchor; a presenter; (less commonly) a commentator;
(less commonly) a master of ceremonies,
Though the announcer said the show would begin at thirty minutes past six, the show did not begin until it was twenty minutes past seven.
An announcer at any railway station must be able to speak at least three languages in some countries in Asia.
Men with loud and clear voice and a bit of humour in their announcements had been in great demand as circus announcers until electric public address system was introduced.