Meaning of “but” - Learner’s Dictionary

but

conjunction us uk strong /bʌt/ weak /bət/
He's not handsome but he's really nice.I tried to persuade her but she wouldn't listen.Jim liked her but I didn't.He would have come but he's too ill.I tried to move forward but the wheels had locked.
OPPOSITE INFORMATION

A1 used to introduce something new that you say, especially something that is different or the opposite from what you have just said:

I'd drive you there, but I don't have my car.
The tickets were expensive, but the kids really enjoyed it.
EXPLAINING WHY

used before you say why something did not happen or is not true:

I was going to go to his party, but I was sick.
SHOWING SURPRISE

used to show that you are surprised about what someone has just said:

'Tim is leaving.' 'But why?'
CONNECTING PHRASES

used to connect 'excuse me' or 'I'm sorry' with what you say next:

Excuse me, but would you mind shutting the door?

(Definition of “but conjunction” from the Cambridge Learner’s Dictionary © Cambridge University Press)