How do I Say and Write
"Sir" in Japanese?

Pronunciation : Sir
Part of Speech : n.
Etymology : [OE. sire, F. sire, contr. from the nominative L. senior an elder, elderly person, compar. of senex,senis, an aged person; akin to Gr. sana, Goth. sineigs old, sinista eldest, Ir. & Gael. sean old, W. hen. Cf. Seignior, Senate, Seneschal, Senior, Seno
Definition : 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.
Source : Webster's Unabridged Dictionary, 1913