sir /ˈsɝ/
 U先生;爵士
 Sir 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.
    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.
 ◄ ►
 sir
      n 1: term of address for a man
      2: a title used before the name of knight or baronet