megalosaur vs. megalosaurus
maniraptor vs. oviraptorid
millepede vs. millipede
milliped vs. millipede
mite vs. pinch
monal vs. monaul
momot vs. motmot
merganser vs. sheldrake
marabou vs. marabout
mole vs. seawall
mol vs. mole
mollusc vs. mollusk
mollusk vs. shellfish
meow vs. mew
mew vs. miaou
mew vs. miaow
mew vs. miaul
malamute vs. malemute
meerkat vs. mierkat
mantid vs. mantis
mayfly vs. shadfly
monarch vs. sovereign
mouse vs. shiner
muskrat vs. musquash
mare vs. maria
mule vs. scuff
markhoor vs. markhor
moufflon vs. mouflon
megatherian vs. megatheriid
man vs. world
man vs. mankind
man vs. piece
man vs. serviceman
man vs. valet
monkey vs. scamp
monkey vs. rascal
monkey vs. rapscallion
monkey vs. scalawag
monkey vs. scallywag
monkey vs. tinker
monkey vs. putter
monkey vs. potter
monkey vs. tamper
mastodon vs. mastodont
moonfish vs. opah
maiger vs. maigre
mudskipper vs. mudspringer
metamere vs. somite
mola vs. sunfish
madhouse vs. nuthouse
marihuana vs. marijuana
mantle vs. pall
mantel vs. mantle
mantelpiece vs. mantle
mantle vs. mantlepiece
mantle vs. pallium
mag vs. magazine
mangonel vs. onager
mail vs. post
muffler vs. silencer
motorway vs. pike
munition vs. ordnance
mow vs. pout
manikin vs. mannikin
mailbag vs. postbag
mailboat vs. packet
manse vs. residence
mansion vs. residence
mailbox vs. postbox
machete vs. matchet
machete vs. panga
mantelet vs. mantilla
mantelet vs. mantlet
mantrap vs. smasher
main vs. primary
main vs. principal
main vs. master
map vs. represent
macintosh vs. mackintosh
mainstay vs. pillar
marimba vs. xylophone
maisonette vs. maisonnette
maiolica vs. majolica
marlinespike vs. marlinspike
marlinespike vs. marlingspike
marquee vs. marquise
marquee vs. pavilion
marchioness vs. marquise
marqueterie vs. marquetry
masher vs. wolf
manger vs. trough
mangle vs. maul
mastaba vs. mastabah
master vs. original
master vs. passkey
master vs. schoolmaster
maestro vs. master
master vs. professional
master vs. skipper
master vs. overlord
master vs. superior
master vs. subdue
master vs. overcome
master vs. surmount
MDMA vs. methylenedioxymethamphetamine
merchandise vs. ware
merchandise vs. product
merchandise vs. trade
metro vs. underground
match vs. mates
match vs. pit
match vs. tally
match vs. touch
meerschaum vs. sepiolite
mescaline vs. peyote
mess vs. sight
mess vs. messiness
mess vs. muss
mess vs. mussiness
memorial vs. monument
memorial vs. remembrance
monument vs. repository
memory vs. storage
memory vs. retention
memory vs. remembering
meter vs. time
maul vs. sledge
maul vs. sledgehammer
meterstick vs. metrestick
menagerie vs. zoo
mahlstick vs. maulstick
methadon vs. methadone
maze vs. tangle
maze vs. snarl
masjid vs. musjid
missile vs. projectile
monstrance vs. ostensorium
miter vs. mitre
mooring vs. slip
mouth vs. mouthpiece
mouth vs. talk
millrace vs. millrun
mixer vs. sociable
mimeo vs. mimeograph
mizen vs. mizzen
mizzen vs. mizzenmast
mizenmast vs. mizzen
morphia vs. morphine
mocassin vs. moccasin
mortice vs. mortise
mosaic vs. photomosaic
minibike vs. motorbike
mold vs. mould
mildew vs. mold
mold vs. shape
micrometer vs. micron
minisub vs. minisubmarine
microphone vs. mike
mould vs. shape
motif vs. theme
microwave vs. nuke
moldboard vs. mouldboard
motorboat vs. powerboat
mint vs. sight
mint vs. strike
muffle vs. stifle
mug vs. physiognomy
mug vs. phiz
mug vs. smiler
mug vs. mugful
muller vs. pestle
muller vs. pounder
muller vs. muser
muller vs. ponderer
muller vs. ruminator
mileometer vs. odometer
milometer vs. odometer
mall vs. promenade
marionette vs. puppet
mepacrine vs. quinacrine
mainsheet vs. tack
max vs. scoop
mop vs. swab
mop vs. pout
macadam vs. tarmacadam
monocycle vs. unicycle
motortruck vs. truck
mawkishness vs. sentimentality
mawkishness vs. mushiness
mawkishness vs. soupiness
mawkishness vs. sloppiness
mushiness vs. pulpiness
muscle vs. muscularity
muscularity vs. sinew
muteness vs. silence
muteness vs. mutism
moroseness vs. sourness
moroseness vs. sullenness