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." "In the election of a sir so rare."
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."
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."
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."
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