sir is one of the 1000 most common headwords.
single - sir - sister
See also Sir

Pronunciation change

Noun change

Singular
sir

Plural
sirs

  1. (countable) You use sir to speak or write to a man formally to be polite.
    Excuse me, sir, could you tell me where the nearest bookstore is?
  2. Sir is a title used before certain men's names.