sir
US /sɝː/
UK /sɝː/
1.
used as a polite or respectful way of addressing a man, especially one in a position of authority or who is older than the speaker
:
•
Excuse me, sir, could you tell me the way to the station?
•
Yes, sir, I understand.
2.
used as a title before the name of a knight or baronet
:
•
Sir Isaac Newton was a brilliant scientist.
•
The Queen knighted him, and he became Sir John.