1.
( of an actor ) to walk onto the stage
2.
( of a player ) to join a team during a game :
Owen came on for Brown ten minutes before the end of the game.
3.
to improve or develop in the way you want :
The project is coming on fine.
4.
used in orders to tell sb to hurry or to try harder :
Come on! We don't have much time.
Come on! Try once more.
5.
used to show that you know what sb has said is not correct :
Oh, come on—you know that isn't true!
6.
(usually used in the progressive tenses) ( of an illness or a mood ) to begin :
I can feel a cold coming on.
I think there's rain coming on.
[+ to inf]
It came on to rain.
7.
( of a TV programme, etc. ) to start :
What time does the news come on?
8.
to begin to operate :
Set the oven to come on at six.
When does the heating come on?