1. A man of social authority and dignity; a lord; a master; a gentleman; -- in this sense usually spelled sire. [Obs.]
He was crowned lord and sire. --Gower.
In the election of a sir so rare. --Shak.
2. A title prefixed to the Christian name of a knight or a baronet.
Sir Horace Vere, his brother, was the principal in the active part. --Bacon.
3. An English rendering of the LAtin Dominus, the academical title of a bachelor of arts; -- formerly colloquially, and sometimes contemptuously, applied to the clergy.
Instead of a faithful and painful teacher, they hire a Sir John, which hath better skill in playing at tables, or in keeping of a garden, than in God's word. --Latimer.
4. A respectful title, used in addressing a man, without being prefixed to his name; -- used especially in speaking to elders or superiors; sometimes, also, used in the way of emphatic formality. “What's that to you, sir?”
Note: ☞ Anciently, this title, was often used when a person was addressed as a man holding a certain office, or following a certain business. “Sir man of law.” “Sir parish priest.”
Sir reverance. See under Reverence, n.
n 1: term of address for a man
2: a title used before the name of knight or baronet