- Kundt tube
- L capture
- L electron
- lability
- labyrinth
- lading space
- lag
- lag theorem
- lagging coil
- lagging load
- lagging phase
- knock-sedative
- Knudsen effect
- Knudsen number
- knurled fin
- Kondo effect
- konisphere
- Kossel effect
- Kruskal coordinates
- krypton0xenon mixture
- lac
- lambda leak
- lambda point
- lamella
- laminar layer
- laminate
- laminated contact
- laminated foil
- laminated frame
- lamination
- lamination factor
- laminography
- lamp
- lamp core
- lamp depreciation
- lamp holder
- land effect
- land return
- Landau damping
- landing
- landing switch
- landscape
- landscape lens
- lantern pinion
- lantern wheel
- lanthanide
- lanthanide ferrite
- lap dissolve
- lap welding
- lap winding
- lapel microphone
- Laplace operator
- Laplace transform
- Laplace transformation
- Laplacien
- Larmor precession
- larmor radius
- laser alloying
- laser welding
- latch circuit
- latent
- lateral deformation
- Latour doubler
- lattice absorption
- lattice distortion
- lattice vibration
- Laue method
- launcher
- Laval nozzle
- Lawson criterion
- lead plate
- lead-in
- leader stroke
- leading current
- leading line
- leakage air
- leakage coefficient
- leakage flux
- leakage losses
- Larmor formula
- Larmor orbit
- laser cooling
- laser interferometry
- laser resonator
- latency
- lateral magnification
- latitude effect
- latitudinal variation
- lattice tower
- lattice winding
- launching pad
- lay ratio
- leading load
- leaf valve
- leak
- leak detection
- leak localize
- leakage reactance
- leaky
- leased circuit