sir

/sɜːr/

/sɝː/ (also Sir) formal

Definition

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 madam, Miss, MsFriendly and unfriendly terms of address › 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.Written greetingsLetters, notes and cards 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 womanWritten greetingsLetters, notes and cards

(Definition of sir noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)