From Longman Dictionary of Contemporary Englishsirsir /sə; strong sɜː $ sər strong sɜːr/ ●●● S1 W3 noun 1 spokenTALK TO somebodyNAME OF A PERSON used when speaking to a man in order to be polite or show respect ‘Report back to me in an hour, sergeant.’ ‘Yes, sir.’ Can I help you, sir? Sir! You dropped your wallet. → madam(1), ma'am2 → Dear Sir/Sirs3 → Sir4 British English spokenTALK TO somebodyTEACH used by children at school when speaking to or talking about a male teacher Sir, I’ve forgotten my homework. Look out – sir’s coming back! → miss2(4)5 → no/yes sir!
Examples from the Corpussir• Anagrams and word puzzles are not in my line of country, sir.• Dear Sir or Madam..• Not esquire, sir, lord or anything like that.• The bodies are here, sir.• Would you need to speak to him, sir?• You needn't be jealous, sir.• Excuse me, sir. Is this your jacket?• It isn't all it sounds, sir, but they tell me it's a start.• "Are you on duty tonight, Corporal?" "Yes, sir."SirSirNAME OF A PERSONHIGH POSITION OR RANKa title used before the first name of a knight or baronet Sir Paul McCartney Sir Jasper → sir
Examples from the CorpusSir• Sir James WilsonOrigin sir (1200-1300) → SIRE1