\Sir\, n. [OE. sire, F. sire, contr. from the nominative L.
senior an elder, elderly person, compar. of senex,senis, an
aged person; akin to Gr. ??? old, Skr. sana, Goth. sineigs
old, sinista eldest, Ir. & Gael. sean old, W. hen. Cf.
{Seignior}, {Senate}, {Seneschal}, {Senior}, {Senor},
{Signor}, {Sire}, {Sirrah}.]
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.
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.'' --Chaucer.
{Sir reverance}. See under {Reverence}, n.