- (physics) Laser-Induced Reaction
- (telecom) Local Interconnection Region, an alternative to exchanged-based interconnection strategy for Competitive Local Exchange Carriers (CLECs)
lir - Computer Definition
The local organization responsible for assigning Internet Protocol (IP) addresses to Internet Service Providers (ISPs). The LIR receives IP address assignments from a National Internet Registry (NIR) or Regional Internet Registry (RIR) that receives address assignments from the Internet Assigned Numbers Authority (IANA). See also IANA, IP, IP address, ISP, NIR, and RIR.