1. Acronym for Serial Line Internet Protocol, SLIP is a serial packet protocol used to connect a remote computer to the Internet using modems or direct serial lines, SLIP requires an Internet provider with special SLIP accounts or a shell account a SLIP emulator such as TIA(tm) or SLiRP. From KADOWKEV

2. Serial Line Internet Protocol - A communication method that allows a personal computer to connect directly to the Internet using a standard telephone line. It preceded PPP as the means through which access to the Internet could be achieved. From Linux Guide @FirstLinux