A term of respectful address to men.
A title of baronets and knights.
If you will have it, Sir- there it is! – Man and Wife by Wilkie Collins
I should like to do so, sir. – The Thin Red Line; and Blue Blood by Arthur Griffiths
How you may feel, Sir, has nothing to do with it. – The House by the Church-Yard by J. Sheridan Le Fanu