China 
Africa 
- Low-discrepancy sequences
- Low-emissivity
- Low-energy house
- Low-frequency radar
- Low-impact development
- Low-intensity pulsed ultrasound
- Low-iron glass
- Low-k
- Low-level
- Low-level design
- Low-level laser therapy
- Low-level radioactive waste
- Low-level waste
- Low-pass filters
- Low-power
- Low-power electronics
- Low-pressure area
- Low-rank approximation
- Low-rise
- Low-rolling resistance tires
- Low-speed vehicle
- Low-tech
- Low-temperature distillation
- Low-temperature thermal desalination
- Low-velocity zone
- Low-voltage network
- Lower envelope
- Lower flammability limit
- Lower flammable limit
- Lower motor neuron
- Lower oceanic crust
- Lower respiratory tract infections
- Lower shoreface
- Lua
- Lubricants
- Lubrication
- Lubrication theory
- Lubricity
- Lucene
- Luciferase
- Luciferin
- Ludwigite
- Lug nuts
- Luge
- Luggin capillary
- Luggin probe
- Lugs
- Lumbar
- Lumbar arteries
- Lumbar plexus
- Lumbar puncture
- Lumbar vertebrae
- Lumen maintenance
- Luminance
- Luminescence
- Luminescence dating
- Luminescent solar concentrator
- Luminol
- Luminophore
- Luminosity
- Luminosity function
- Luminous efficacy
- Luminous efficiency function
- Luminous energy
- Luminous flame
- Luminous flux
- Luminous intensity
- Lump sum contract
- Lumpectomy
- Lumped element model
- Lumped-element model
- Lunar base
- Lunar day
- Lunar month
- Lunar rover
- Lunar soil
- Lundquist number
- Luneburg lens
- Lung
- Lung biopsy
- Lung capacity
- Lung compliance
- Lung infarction
- Lung infection
- Lung transplantation
- Lung volumes
- Lung-on-a-chip
- Lupus
- Lupus erythematosus
- Lupus nephritis
- Luster
- Lustre
- Luteal phase
- Lutein
- Luteolin
- Lutetium
- Lutetium-177
- Lutidine
- Lutite
- Lux
- Lwip
- Lyapunov dimension
- Lyapunov equation
- Lyapunov exponents
- Lyapunov functions
- Lyapunov optimization
- Lyapunov redesign
- Lyapunov stability
- Lyases
- Lycopene
- Lye
- Lyman-alpha line
- Lyme disease
- Lymph
- Lymph node biopsy
- Lymph nodes
- Lymphadenopathy
- Lymphangiectasia
- Lymphangiogenesis
- Lymphangiography
- Lymphatic system
- Lymphatic vessels
- Lymphedema
- Lymphoblasts
- Lymphocyte function-associated antigen 1
- Lymphocyte-activation gene 3
- Lymphocytes
- Lymphocytic leukemia
- Lymphocytopenia
- Lymphocytosis
- Lymphoid hyperplasia
- Lymphoid leukemia
- Lymphokines
- Lymphoma
- Lymphotoxin
- Lynch syndrome
- Lyocell
- Lyot filter
- Lysimeter
- Lysine
- Lysis
- Lysis buffer
- Lysogenic
- Lysogenic cycle
- Lysophosphatidylcholine
- Lysosomal enzymes
- Lysosomes
- Lysostaphin
- Lysozyme
- Lysyl oxidase