| L4/5 | Lumbar vertebrae 4 and 5 interspace 
| Others |
| L4D | Left 4 Dead
| Others |
| L4D2 | Left 4 Dead 2
| Others |
| L4F | Leaders for the Future
| Others |
| L4F | Love 4 Furniture
| Others |
| L4G | Language of Fourth Generation
| Others |
| L4G | Linux for Government
| Others |
| L4L | Like for Like
| Others |
| L4N | Live for Now
| Others |
| L5-S1 | Lumbar Vertebrae 5 to Sacral Vertebrae 1 connection
| Others |
| L52 | Oceano County Airport, Oceano, California USA
| Others |
| L57 | Hidden Hills Airport, Pahrump, Nevada USA (closed)
| Others |
| L5D | Luxury Five Cylinder Diesel
| Others |
| L5E | Luxury Five Cylinder Economic
| Others |
| L6M | Last 6 Months
| Others |
| L70ETC | Level 70 Elite Tauren Chieftan
| Others |
| L77 | Chiriaco Summit Airport, Chiriaco, California USA
| Others |
| L7C | Lotus Seven Club
| Others |
| L7D | Last 7 Days
| Others |
| L7OC | Lotus Seven Owners Club
| Others |
| L7R | Lotus Seven Register
| Others |
| L7R | Lotus Seven Replica
| Others |
| L7S | Lucky 7's
| Others |
| L85 | Leiden-85 cohort
| Others |
| L8R G8R | Later Gater
| Others |
| L8R G8R | Later Gator
| Others |
| L8R G8R | See you Later, Alligator
| Others |
| L<3L | I'm laughing at you, but I still love you
| Others |
| LA | Lab Assistant
| Others |
| LA | Lack Of Action
| Others |
| LA | Lacking Airspeed
| Others |
| LA | Lactate Aqueous
| Others |
| LA | Lactic Acidosis
| Others |
| LA | Ladakh
| Union Territory |
| LA | Lake Athabasca
| Others |
| LA | Lambaste Arnold
| Others |
| LA | Lan And Audio
| Others |
| LA | Land Of Apathy
| Others |
| LA | Landeck Austria
| Others |
| LA | Landscape Advocacy
| Others |
| LA | Landscape Architects
| Others |
| LA | Lane
| Others |
| LA | Language Assistant
| Others |
| LA | Lansing Area
| Others |
| LA | Lanthanum
| Element |
| LA | Lard A
| Others |
| LA | Large Amplitude
| Others |
| LA | Large Area
| Others |
| LA | Laser Ablation
| Others |
| LA | Laser Angioplasty
| Others |