sir

/sɜr/
noun
  1. A polite way to address a man, especially one you do not know or one in a position of authority.
    • The teacher said, 'Sir, please take your seat.'
    • Yes, sir, I will follow your orders.
    • Excuse me, sir, can you tell me the time?
  2. A title used before the first name of a knight or baronet in the United Kingdom.
    • Sir Isaac Newton is famous for his work in physics.
    • Sir Paul McCartney was knighted for his services to music.
    • The queen knighted him, and he became Sir John.
  3. Used as a formal salutation in letters or emails to a man whose name you do not know.
    • Sir, we have received your complaint and will respond soon.
    • To whom it may concern: Dear Sir or Madam,
    • Dear Sir, I am writing to apply for the position.
Antonyms
What does "sir" mean? | whatsthatwordmean | whatsthatwordmean