Meaning of “sir” in the English Dictionary

"sir" in British English

See all translations

sirnoun [ as form of address ]

uk /sɜːr/ us /sɝː/ also Sir formal

B1 used as a formal and polite way of speaking to a man, especially one who you are providing a service to or who is in a position of authority:

Would you like to see the menu, sir?
"Did you hear what I said?" "Yes, Sir."
Compare

mainly UK sometimes used by children to address or refer to teachers who are men:

Can I go to the toilet, sir?

Indian English used after the name of a man, especially one who is in a position of authority, in order to be polite or show respect:

John Sir
Dear Sir

B2 used to begin a formal letter to a man whose name you do not know. "Dear Sirs" is an old fashioned way of beginning a letter to a company.

Dear Sir or Madam

used to begin a formal letter when you do not know if the person you are writing to is a man or a woman

More examples

Idiom(s)

Sirnoun

uk strong /sɜːr/ weak /r/ us /sɝː/ //

used as the title of a knight (= a man who has been given a rank of honour by a British king or queen), with a first name or with both first and family names, but never with just the family name:

Sir Walter (Scott)

More examples

  • Sir Geoffrey will see you now.
  • Sir Harold and Lady Wilson arrived at eight.

(Definition of “sir” from the Cambridge Advanced Learner’s Dictionary & Thesaurus © Cambridge University Press)

"sir" in American English

See all translations

sirnoun [ C ]

us /sɜr/

sir noun [ C ] (USED TO ADDRESS)

a polite word used to address a man:

Excuse me, sir, do you know what time it is?

Sir is used at the beginning of a formal letter to a man you do not know:

Dear Sir

sir noun [ C ] (USED AS TITLE)

also Sirused as a title with the first or full name of a man given a rank of honor by a king or queen

(Definition of “sir” from the Cambridge Academic Content Dictionary © Cambridge University Press)

"Sir" in Business English

See all translations

Sirnoun [ S ]

uk /sɜːr/ us formal

a formal and polite way of speaking to a man:

May I help you, Sir?
Dear Sir

the usual way of beginning a formal letter to a man whose name you do not know:

Dear Sir, I am writing to complain about the quality of the service I received last week.
Dear Sir or Madam

used to begin a formal letter when you do not know whether the person you are writing to is a man or a woman:

Dear Sir or Madam, I am writing to inform you that I wish to cancel my credit card.
Dear Sirs old-fashioned

used to begin a letter to a company when you do not have someone's name to write to directly

Compare

(Definition of “Sir” from the Cambridge Business English Dictionary © Cambridge University Press)