1.
You say ‘Come on’ to someone to encourage them to do something they do not much want to do. (SPOKEN)
Come on Doreen, let’s dance.
= come along
CONVENTION
2.
You say ‘Come on’ to someone to encourage them to hurry up. (SPOKEN)
= come along
CONVENTION
3.
If you have an illness or a headache coming on, you can feel it starting.
Tiredness and fever are much more likely to be a sign of flu coming on.
PHRASAL VERB: usu cont, V P
4.
If something or someone is coming on well, they are developing well or making good progress.
Lee is coming on very well now and it’s a matter of deciding how to fit him into the team...
= come along
PHRASAL VERB: usu cont, V P adv
5.
When something such as a machine or system comes on, it starts working or functioning.
The central heating was coming on and the ancient wooden boards creaked.
? go off
PHRASAL VERB: V P
6.
If a new season or type of weather is coming on, it is starting to arrive.
Winter was coming on again...
I had two miles to go and it was just coming on to rain.
PHRASAL VERB: usu cont, V P, it V P to-inf