Sir is an honorific address used in a number of situations in many anglophone cultures. The term can be used as a formal prefix, especially in the Commonwealth, for males who have been given certain honours or titles (such as knights and baronets), where usage is strictly governed by law and custom.
The term is also commonly used as a respectful way to address a man, usually of superior social status or holding a commissioned military rank. Equivalent terms of address to females are ‘ma’am’ or ‘madam’ in most cases, or in the case of a young woman, girl, or unmarried woman who prefers to be addressed as such, ‘miss’. The equivalent term for a knighted woman or baronetess is Dame, or ‘Lady’ for the wife of a knight or baronet.
Mum, mom; diminutive of mother.
A man of a higher rank or position.
A respectful term of address to a man of higher rank or position, particularly:
to a knight or other low member of the peerage.
“Just be careful. He gets whingy now if you don’t address him as Sir John.”
to a superior military officer.
“Sir, yes sir.”
A respectful term of address to any male, especially if his name or proper title is unknown.
“Excuse me, sir, do you know the way to the art museum?”
Used as an intensifier after yes or no.
“Sir, yes sir.”
To address (someone) using “sir”.
“Sir, yes, sir!
Don’t you sir me, private! I work for a living!”
“my mam would have had a fit if I’d gone out dressed like that”
“I had to look after the other children while Mam worked”
a term of respectful or polite address used for any woman
“‘You all ride them horses down here?’ ‘Yes, mam.’”