- line integral
- line spectrum
- linear collider
- linear disc
- linear disk
- linear dispersion
- linear ionization
- linear magnification
- linear range
- linear resistor
- linear vibrations
- linkage
- liquid ammonia
- liquid helium
- liveness
- lip reading
- liquid fuel
- liquid paraffin
- live display
- live oil
- load resistance
- loading coil
- loading mechanism
- local control
- local oscillation
- lock
- locking mechanism
- lip microphone
- liquid chlorine
- local oscillator
- load diagram
- logarithmic decrement
- loop
- loose buffer
- loose buffering
- local vibration
- locating key
- lock pin
- logatom
- Lorentz equation
- Lorenz constant
- Lorenz unit
- Loschmidt number
- lubricating pump
- longitudinal component
- longitudinal magnetization
- longitudinal matinification
- lossy line
- loudspeaker baffle
- lubricating chart
- lumen
- lumen-hour
- lumen-second
- lumiaire
- luminescent discharge
- luminescent screen
- luminosity coefficient
- luminous exitance
- luminous intensity
- lux
- lux value
- lyman series
- machine processor
- macroscopic variable
- magazine back
- magnetic coating
- magnetic confinement
- magnetic constant
- magnetic drag
- magnetic ink
- magnetic latitude
- magnetic moment
- magnetic pull
- magnetic quantities
- magnetic repulsion
- magnetic shell
- magnetic south
- magnetic stirrer
- magnetic torque
- magnetic wire
- magnetostriction constant
- magnetostriction microphone
- magnifying power
- magnitude
- magnus effect
- main excitation
- maintained oscillation
- major key
- major scale
- machining property
- machining quality
- magnesium flashlight
- magnetic attraction
- magnetic bottle
- magnetic deflection
- magnetic energy
- magnetic layer
- magnetic neutralization
- magnetized plasma
- magnetoplasma