also clapped out. adjective [usually ADJECTIVE noun] If you describe a person or a machine as clapped-out, you mean that they are old and no longer able to work properly. [British, informal, disapproval]

Why do we say clapped out?

It goes back the world's oldest profession. When they are too sick to carry on their duties they are considered Clap-ped out. Therefore they are finished. It could also be after 13 curtain calls the audience is clapped out and therefore finished.

What does clapped out mean in British slang?

chiefly British. : worn-out also : tired.