LAN - Local Area Network - a computer network that links devices within a building or group of adjacent buildings
LAT - Large Area Telescope (Microquasar radio-emitting gas jets)
LCROSS - Lunar Crater Observation and Sensing Satellite (Moon water)
LDL - low-density lipoproteins - bad cholesterol (Olive oil turkey)
LDW - Lane Departure Warning
LELA - Linksys EasyLink Advisor (Cisco media router)
LIN - Local Interface Network in Automotive Electronics
LTE - Long Term Evolution (Verizon 4G LTE network)