Send off

EMIT

Think of what a lightbulb or radio signal does when it releases energy or waves into the air.

Send off" is a straightforward definition for "emit," which means to discharge or give out something like light, sound, or energy. The clue plays on the literal meaning of sending something away or releasing it, which aligns perfectly with how "emit" is used in everyday language. No hidden wordplay or tricks—just a direct match between the clue and the answer.