China 
Africa 
- Lead dioxide
- Lead frame
- Lead glass
- Lead iodide
- Lead magnesium niobate
- Lead oxide
- Lead paint
- Lead phosphate
- Lead poisoning
- Lead selenide
- Lead shielding
- Lead smelting
- Lead sulfate
- Lead sulfide
- Lead tin telluride
- Lead titanate
- Lead zirconate titanate
- Lead(ii) acetate
- Lead(ii) oxide
- Lead-210
- Lead-acid batteries
- Lead-acid battery
- Lead-cooled fast reactor
- Lead-lag compensator
- Leader election
- Leadership
- Leading
- Leading edges
- Leading order
- Leading zeros
- Leading-edge slats
- Leadscrew
- Leaf class
- Leaf fiber
- Leaf litter
- Leaf springs
- Leaflet
- Leafy
- Leak detection
- Leakage
- Leakage current
- Leakage inductance
- Leaks
- Leaky bucket
- Leaky feeder
- Leaky integrator
- Leaky wave antenna
- Lean
- Lean Six Sigma
- Lean body mass
- Lean burn
- Lean construction
- Lean manufacturing
- Lean thinking
- Lean-burn
- Leap years
- Learnable evolution model
- Learning analytics
- Learning automaton
- Learning curve
- Learning disabilities
- Learning disability
- Learning object metadata
- Learning objects
- Learning organization
- Learning rate
- Learning rule
- Learning to rank
- Learning-by-doing
- Leased line
- Least absolute deviations
- Least count
- Least fixed point
- Least frequently used
- Least squares
- Least trimmed squares
- Least-angle regression
- Least-squares adjustment
- Least-squares spectral analysis
- Least-squares support vector machine
- Least-upper-bound property
- Leaving group
- Lebesgue integral
- Lebesgue integration
- Lebesgue measure
- Leblanc process
- Lecithin
- Lectins
- Ledeburite
- Ledinegg instability
- Lees
- Left and right
- Left anterior descending artery
- Left coronary artery
- Leftover hash lemma
- Leg
- Legacy
- Legacy systems
- Legal expert systems
- Legal person
- Legendre functions
- Legendre pseudospectral method
- Legendre transformation
- Legged robot
- Leghemoglobin
- Legionella pneumophila
- Lehr
- Leibniz integral rule
- Leibniz's notation
- Leidenfrost effect
- Leiomyosarcoma
- Leishmaniasis
- Leloir pathway
- Lemmas
- Lemmatisation
- Lemmatization
- Lemniscate
- Lemniscus
- Lempel-Ziv complexity
- Length
- Length constant
- Length contraction
- Length measurement
- Length of a module
- Length of stay
- Length scale
- Lennard-Jones potential
- Lens
- Lens antennas
- Lens capsule
- Lens flare
- Lenses
- Lenslet
- Lenticular bedding
- Lentiform nucleus
- Lentinan
- Leonardite
- Lepidocrocite
- Lepidolite
- Leprosy
- Leptin
- Leptin receptor
- Leptospirillum ferriphilum
- Leptospirosis
- Lesions
- Leslie matrix
- Lesser trochanter
- Lesser tubercle
- Lessons learned
- Lestaurtinib