- Melanoma
- Mellifluent
- Mellifluous
- Melodic
- Meltingly
- Member
- Membraneous
- Membranous
- Memento
- Memorize
- Menace
- Menacing
- Mend fences
- Mendacity
- Mender
- Mendicant-beggar
- Mendicants bowl
- Mene maculata
- Mensal
- Mensurable
- Mensus
- Mental
- Mental aberration
- Mental conception
- Merriment
- Mental home
- Mental illness
- Mental peace
- Mentionable
- Menu
- Mercantile law
- Merchant navy
- Merchant ship
- Mercifully
- Mercilessness
- Meretricious
- Merge
- Meridian
- Merit
- Merited
- Merman
- Merrier
- Merrily
- Merry
- Merry-go-round
- Mesmerise
- Mesmerize
- Mess
- Message
- Messengers
- Messiah
- Messianic
- Messieurs
- Messily
- Messy
- Met
- Metabolic
- Metalanguage
- Metallic
- Metallic currency
- Metallic lustre
- Metallic sound
- Metallurgist
- Metallurgy
- Metalwork
- Metamorphic
- Metamorphic rock
- Metaphoric
- Metaphorical
- Metaphysics
- Mete out
- Meteoroid
- Methodologist
- Metonymy
- Metro
- Metrology
- Mettlesome
- Mezzotint
- Miasmatic
- Miasmic
- Micaceous
- Micro
- Micro floppy disk
- Microchip
- Microcomputer
- Microcosm
- Microfiche
- Microfilm
- Microphone
- Microprocessor
- Microscope
- Micturition
- Mid
- Mid-calf
- Mid-day meal
- Mid-day sun
- Mid-may
- Mid-on
- Midage
- Middle ages