1.
( formal ) used to tell sb that you are sorry for sth you have said or done :
I beg your pardon, I thought that was my coat.
2.
used to ask sb to repeat what they have just said because you did not hear :
'It's on Duke Street.' 'I beg your pardon.' 'Duke Street.'
3.
( especially BrE ) used to tell sb that you are offended by what they have just said or by the way that they have said it :
'Just go away.' 'I beg your pardon!'