- macro-parameter
- magnetic amplifier
- magnetic code
- magnetic coil
- magnetic core
- magnetic cycle
- magnetic mirror
- magnetic recorder
- magnetic tape
- mailbox name
- mailing label
- main busbar
- main output
- main reflector
- mainline module
- maintenance data
- maintenance personnel
- maintenance service
- maintenance status
- Management board
- management center
- maneuver
- manned station
- magnetic disturbance
- magnetic equator
- magnetization
- magnetodiode
- magnetographic printer
- magnetospheric cleft
- magnetron oscillator
- mailing address
- main exchange
- main lobe
- main stage
- mains failure
- maintenance instructions
- maintenance system
- maintenance tower
- management account
- manager station
- management centre
- management programme
- management repot
- management support
- mandatory indicator
- manned
- manning table
- manual input
- manual operation
- manual sort
- maneto switchboard
- manual exchange
- manual install
- manual sorting
- manual system
- manual working
- many-particle
- marginal distribution
- marital status
- mark pulse
- mark scanning
- marginal occupancy
- mark parity
- marker
- marker frames
- marking sequence
- MAROTS system
- maser pump
- mask alignment
- mass expulsion
- mass number
- mass storage
- mast antenna
- master frequency
- master mask
- map file
- mapping device
- Marconi antenna
- margin control
- margin indent
- marginal capacity
- marginal check
- marginal test
- MARISAT system
- maritime satellite
- mark frequency
- mark recognition
- mathematic simulation
- mathematical statistic
- matrix configuration
- matrix printing
- matrix rotation
- mattress antenna
- maximum sensitivity
- maximum signal
- maximum sunspot
- mean attenuation
- mean expectation
- mean loudness
- measured quantity