- Microprocessor
- Microscope
- Micturition
- Mid
- Mid-calf
- Mid-day meal
- Mid-day sun
- Mid-may
- Mid-on
- Midage
- Middle ages
- Middle line
- Middle tone
- Middlebrow
- Middlemen
- Midget
- Midnight
- Midrib
- Midshipman
- Midsummer madness
- Midterm
- Miff
- Miffed
- Might
- Mighty
- Mighty works
- Migratory
- Milch
- Milching a cow
- Mildly
- Marl
- Maying
- Murrain
- Malingerer
- Mall
- Miscellanea
- Moan
- Moil
- Monarchical
- Monarchism
- Macabre
- Macadamization
- Macerate
- Maceration
- Machete
- Machiavellian
- Machinator
- Machine
- Machine instruction
- Machine run
- Macho
- Mackerel
- Macro
- Macsyma
- Maculation
- Mad fellow
- Maddar plant
- Madded
- Maddhwacharya
- Mademoiselle
- Madonna
- Madrid
- Mafia
- Magic
- Magical
- Magisterially
- Magnesia
- Magnet
- Magnetic
- Magnetic attraction
- Magnetic stripe
- Magnetic tape
- Magnetise
- Magnetism
- Magnetize
- Magnificable
- Magnolia
- Magnum
- Magnum opus
- Magpie
- Maid
- Maidan
- Maiden
- Maiden speech
- Maidens
- Mail order
- Maillot
- Maintaining
- Mait
- Majestic
- Make a beast of oneself
- Make a capital out of
- Make a concession
- Make a dead set at
- Make a go of it
- Make a hole in
- Make a merit of
- Make for
- Make a move