Definition from macmillandictionary.com
Melissa had her new dress on.
I couldn’t see properly. I didn’t have my glasses on.
Of course he was cold – he’d got practically nothing on.
I can’t talk to him while he’s got the television on.
We haven’t had the air conditioning on all summer.
They haven’t got anything on Marlowe, so they can’t arrest him.
Do you have anything on for tomorrow afternoon?
He’s having you on: don’t take any notice of him.