Sir is a formal honorific address in English for men, derived from Sire in the High Middle Ages. Both are derived from the old French " Sieur " (Lord), brought to England by the French-speaking Normans, and which now exists in French only as part of "Monsieur" lit. 'my lord'.
The meaning of SIR is a man entitled to be addressed as sir —used as a title before the given name of a knight or baronet and formerly sometimes before the given name of a priest.
SIR definition: a respectful or formal term of address used to a man. See examples of sir used in a sentence.
People sometimes say sir as a very formal and polite way of addressing a man whose name they do not know or a man of superior rank. For example, a shop assistant might address a male customer as sir.
Sir is used at the beginning of a formal letter to a man you do not know: Dear Sir
- a polite form of address (spoken or written) to a man. Excuse me, sir!; He started his letter `Dear Sirs, ...'.
From Middle English sir, unstressed form of sire, borrowed from Old French sire (“master, sir, lord”), from Latin senior (“ older, elder ”), from senex (“old”).
“At ease, lieutenant.” “Yes sir, captain.” Sir, I don't think I was speeding. Sir, can you help me with this math problem? Dinner is ready, sir.
Use the word sir as a formal title for a man. People often use sir to respectfully or politely address someone they don't know well. When you're saying hello to a man who's been knighted by the Queen of England, you should call him sir — it's the official way to address a knight.