- Lightweight protocols
- Lightweighting
- Lignan
- Lignin
- Lignin peroxidase
- Ligninase
- Lignite
- Lignocellulose
- Lignocellulosic biomass
- Lignosulfonates
- Like button
- Like terms
- Likelihood function
- Likelihood principle
- Likelihood ratio
- Likelihood-ratio test
- Likert scale
- Lilliefors test
- Limb
- Limbal stem cells
- Limbic system
- Limdep
- Lime
- Lime mortar
- Lime plaster
- Lime render
- Lime softening
- Lime sulfur
- Limescale
- Limestone
- Limewater
- Liming
- Limit analysis
- Limit comparison test
- Limit inferior and limit superior
- Limit load
- Limit of a sequence
- Limit points
- Limit state design
- Limit superior
- Limit switches
- Limited availability
- Limited-slip differential
- Limiting case
- Limiting factor
- Limiting oxygen concentration
- Limiting oxygen index
- Limiting reagent
- Limits of computation
- Limits of integration
- Limnology
- Limonene
- Limonite
- Limonoids
- Linalool
- Linalyl acetate
- Linamarase
- Lindane
- Lindy Effect
- Line at infinity
- Line bundle
- Line charts
- Line drawing algorithm
- Line element
- Line fitting
- Line graph
- Line integral convolution
- Line laser
- Line numbers
- Line of action
- Line of sight
- Line printer
- Line regulation
- Line search
- Line segment
- Line shaft
- Line signaling
- Line source
- Line-intercept sampling
- Line-of-sight propagation
- Line-replaceable unit
- Linea alba
- Lineage
- Lineaments
- Linear accelerators
- Linear actuator
- Linear algebra
- Linear amplifier
- Linear bounded automaton
- Linear circuit
- Linear classifiers
- Linear code
- Linear combination
- Linear combination of atomic orbitals
- Linear compressor
- Linear control
- Linear density
- Linear differential equation
- Linear discriminant analysis
- Linear dynamical system
- Linear elasticity
- Linear encoders
- Linear epitope
- Linear equation
- Linear filters
- Linear fractional transformations
- Linear functionals
- Linear genetic programming
- Linear group
- Linear independence
- Linear interpolation
- Linear ion trap
- Linear least squares
- Linear logic
- Linear low-density polyethylene
- Linear map
- Linear matrix inequality
- Linear model of innovation
- Linear motion
- Linear motor
- Linear network coding
- Linear no-threshold model
- Linear optics
- Linear park
- Linear polarization
- Linear prediction
- Linear probability model
- Linear programming
- Linear programming relaxation
- Linear range
- Linear referencing
- Linear regression
- Linear regulator
- Linear scheduling method
- Linear search
- Linear separability
- Linear space
- Linear span
- Linear stability
- Linear stage
- Linear subspace
- Linear sweep voltammetry
- Linear system
- Linear temporal logic
- Linear time-invariant system
- Linear topology
- Linear utility
- Linear-fractional programming
- Linear-quadratic-gaussian control
- Linearity