1297, title of honor of a knight or baronet (until 17c. also a title of priests), variant of sire, originally used only in unstressed position. Generalized as a respectful form of address by c.1350; used as a salutation at the beginning of letters from 1425.
SIR 1. An early system on the IBM 650. [Listed in CACM 2(5):16, May 1959]. 2. Serial Infrared. An infraredstandard from IrDA, part of IrDA Data. SIR supports asynchronous communications at 9600 bps - 115.2 Kbps, at a distance of up to 1 metre. [Reference?] (1999-10-14)
Sen"ate\, n. [OE. senat, F. s['e]nat, fr. L. senatus, fr. senex, gen. senis, old, an old man. See Senior, Sir.]1. An assembly or council having the highest deliberative and legislative functions. Specifically: (a) (Anc. Rom.) A body of elders appointed or elected from among the nobles of the nation, and having supreme legislative authority. The senate was thus the medium through which all affairs of the whole government had to pass. --Dr. W. Smith. (b) The upper and less numerous branch of a legislature in various countries, as in France, in the United States, in most of the separate States of the United States, and in some Swiss cantons. (c) In general, a legislative body; a state council; the legislative department of government. 2. The governing body of the Universities of Cambridge and London. [Eng.] 3. In some American colleges, a council of elected students, presided over by the president of the college, to which are referred cases of discipline and matters of general concern affecting the students. [U. S.] Senate chamber, a room where a senate meets when it transacts business. Senate house, a house where a senate meets when it transacts business.