Sir

Part of speech: noun (n.)

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. Nares. 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" Sheridan.