SIR 1. <language> An early system on the {IBM 650}. [Listed in CACM 2(5):16, May 1959]. 2. <standard> Serial Infrared. An {infrared} {standard} 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)