1. /L-P-T/ or /lip'it/ or /lip-it'/ n. 1. Line printer (originally Line Printing Terminal). Rare under Unix, more common among hackers who grew up with ITS, MS-DOS, CP/M and other operating systems that were strongly influenced by early DEC conventions. 2. Local PorT. Used among MS-DOS programmers (and so expanded in the MS-DOS 5 manual). It seems likely this is a backronym. From Jargon Dictionary