1. to make a public statement about something; to tell people something officially
2. to introduce someone or something, especially on radio or television
3. to be a sign that something is coming or about to happen

Examples

• The principal will announce the winner tomorrow.
• The company announced a new product launch.
• She announced her engagement to her family.
• The radio host announced the next song.
• Dark clouds announced the approaching storm.
• The school announced that classes were canceled.
• He announced his retirement from professional sports.