| mangel-wurzel | n. | fodder beet | ||
| mangonel | n. | old war engine for hurling large stones | ||
| manicule | n. | typographic mark of pointing hand: ☞ | ||
| manky | adj. | worthless; unpleasant, foul | British | |
| manometer | n. | instrument for measuring pressure | ||
| manqué | adj. | “That might have been but is not.” [Oxford] | ||
| mansuete | adj. | mild, gentle, meek | ||
| mantelet | n. | short cloak | ||
| mantic | adj. | of or related to divination | ||
| manticore | n. | legendary beast with human face on the body of a lion and the tail of a scorpion or dragon | ||
| mantissa | n. | 1 | decimal part of logarithm | |
| mantissa | n. | 2 | small part or addition of little importance | obsolete |
| mantuamaker | n. | dressmaker | ||
| manubrium | n. | upper part of the sternum connecting to the clavicles | ||
| manustupration | n. | masturbation | archaic | |
| marasmus | n. | wasting away of the body caused by severe malnutrition | ||
| marc | n. | refuse remaining in wine press after the juice is expressed from grapes | ||
| marcel | v. | to make waves in hair through the use of irons; such waved hair | ||
| marcescent | adj. | withered yet still attached | botany | |
| marchioness | n. | wife or widow of a marquis; woman holding rank equal to that of a marquis | British | |
| marchpane | n. | marzipan | ||
| mardy | adj. | grumpy, sulky, moody | British | |
| mare’s nest | n. | illusory discovery | ||
| margarite | n. | a pearl; type of mica supposed to resemble pearls | obsolete | |
| marge | n. | margin | ||
| marish | n. | marsh | ||
| marl | n. | soil composed mainly of clay and lime, often used as fertilizer; to fertilize with marl; [archaic] earth | ||
| marmoreal | adj. | resembling marble or a marble statue | ||
| marplot | n. | one who defeats or spoils a plot or design by meddling or officious intrusion | ||
| Martinmas | n. | November 11, St. Martin’s day | ||
| maslin | n. | rye mixed with wheat; mixed grains (also meslin) | ||
| mast | n. | nuts from oak, chestnut, or beech trees, used as food for swine | ||
| matelot | n. | sailor; buddy | ||
| matriculate | v. | to admit to a college or university, to be enrolled in a college | ||
| matrix | n. | womb, uterus | ||
| matutinal | adj. | of or occurring in the morning | ||
| maudlin | adj. | foolishly tearful or sentimental | ||
| maugre | prep. | notwithstanding, in spite of, despite | archaic | |
| maunch | n. | overly long dropped sleeve fashionable in 14th Century; stylized representation of such a sleeve used as armorial bearing | heraldry | |
| maunder | v. | to mumble, to talk idly, foolishly, or to no real purpose; to move about aimlessly | ||
| maven | n. | expert, aficionado | ||
| mayhap | adv. | perhaps, possibly | archaic | |
| mCi | n. | millicurie | ||
| meddlesome | adj. | interfering or intrusive | ||
| medinal | n. | sodium salt of barbital, first commercial barbiturate | ||
| megaderm | n. | blood-sucking bat of Asia and Africa | ||
| meiosis | n. | figure intentionally portraying something as smaller in size or importance than it actually is | rhetoric | |
| melena | n. | dark tarry stool | ||
| melioration | n. | amelioration, something which makes a thing better | archaic | |
| melismatic | adj. | of song or melody, as opposed to recitative music |
