mole (n.3) Look up mole at Dictionary.com
"breakwater," 1540s, from Middle French môle "breakwater" (16c.), ultimately from Latin moles "mass, massive structure, barrier," from PIE root *mo- "to exert oneself" (cognates: Greek molos "effort," molis "hardly, scarcely;" German mühen "to tire," müde "weary, tired;" Russian majat' "to fatigue, exhaust," maja "hard work").
mole (n.4) Look up mole at Dictionary.com
unit of molecular quantity, 1902, from German Mol coined 1900 by German chemist Wilhelm Ostwald (1853-1912), short for Molekül (see molecule).
molecular (adj.) Look up molecular at Dictionary.com
1823, from molecule + -ar or else from French moléculaire or Modern Latin molecularis. Molecular biology first attested 1950.
molecule (n.) Look up molecule at Dictionary.com
1794, "extremely minute particle," from French molécule (1670s), from Modern Latin molecula, diminutive of Latin moles "mass, barrier" (see mole (3)). A vague meaning at first; the vogue for the word (used until late 18c. only in Latin form) can be traced to the philosophy of Descartes. First used of Modern Latin molecula in modern scientific sense by Amedeo Avogadro (1811).
molehill (n.) Look up molehill at Dictionary.com
also mole-hill, mid-15c., from mole (n.2) + hill (n.).
To much amplifying thinges yt. be but small, makyng mountaines of Molehils. [John Foxe, "Acts and Monuments," 1570]
moleskin (n.) Look up moleskin at Dictionary.com
1660s, from mole (2) + skin (n.).
molest (v.) Look up molest at Dictionary.com
late 14c., "to cause trouble, grief, or vexation," from Old French molester "to torment, trouble, bother" (12c.) and directly from Latin molestare "to disturb, trouble, annoy," from molestus "troublesome, annoying, unmanageable," perhaps related to moles "mass" (see mole (n.3)) on notion of either "burden" or "barrier." Meaning "sexually assault" first attested 1950. Related: Molested; molesting.
molestation (n.) Look up molestation at Dictionary.com
c.1400, "action of annoying or vexing," from Old French molestacion "vexation, harassing," and directly from Medieval Latin molestationem (nominative molestatio), noun of action from past participle stem of molestare (see molest). It meant "the harassing of a person in his possession or occupation of lands" in Scottish law; in English common law it came to mean "injury inflicted upon another."
molester (n.) Look up molester at Dictionary.com
1570s, agent noun from molest.
Moll Look up Moll at Dictionary.com
female proper name, shortened form of Molly, itself familiar for Mary. Used from c.1600 for "prostitute;" meaning "companion of a thief" is first recorded 1823. U.S. sense of "a gangster's girlfriend" is from 1923.
mollification (n.) Look up mollification at Dictionary.com
late 14c., from Old French mollificacion (Modern French mollification), from Medieval Latin mollificationem (nominative mollificatio), noun of action from past participle stem of mollificare (see mollify).
mollified (adj.) Look up mollified at Dictionary.com
1620s, past participle adjective from mollify.
mollify (v.) Look up mollify at Dictionary.com
late 14c., "to soften (a substance)," from Old French mollifier or directly from Late Latin mollificare "make soft, mollify" from mollificus "softening," from Latin mollis "soft" (see melt (v.)) + root of facere "to make" (see factitious). Transferred sense of "soften in temper, appease, pacify" is recorded from early 15c. Related: Mollified; mollifying.
mollusc (n.) Look up mollusc at Dictionary.com
see mollusk.
Mollusca (n.) Look up Mollusca at Dictionary.com
1797, from Modern Latin mollusca, chosen by Linnaeus as the name of an invertebrate order (1758), from neuter plural of Latin molluscus "thin-shelled," from mollis "soft" (see melt (v.)). Linnæus applied the word to a heterogeneous group of invertebrates, not originally including mollusks with shells; the modern scientific use is after a classification proposed 1790s by French naturalist Georges Léopole Chrétien Frédéric Dagobert, Baron Cuvier (1769-1832).
mollusk (n.) Look up mollusk at Dictionary.com
1783, mollusque (modern spelling from 1839), from French mollusque, from Modern Latin Mollusca (see Mollusca), the phylum name. Related: Molluscuous; molluscan.
molly (n.) Look up molly at Dictionary.com
seabird, 1857, short for mollymawk, from Dutch mallemok, from mal "foolish" + mok "gull."
Molly Look up Molly at Dictionary.com
fem. proper name, a familiar form of Mary.
Molly Maguire (n.) Look up Molly Maguire at Dictionary.com
secret society in the mining districts of Pennsylvania, 1867 (suppressed 1876); named for earlier secret society formed in Ireland (1843) to resist payment of rents. From Molly (see Moll) + common Irish surname Maguire. Memebers were said to sometimes wear women's clothing as disguise.
mollycoddle (v.) Look up mollycoddle at Dictionary.com
also molly-coddle, 1870, from a noun (1833) meaning "one who coddles himself," from Molly (pet name formation from Mary), which had been used contemptuously since 1754 for "a milksop, an effeminate man," + coddle (q.v.). Related: Mollycoddled; mollycoddling.
Moloch Look up Moloch at Dictionary.com
Canaanite god said to have been propitiated by sacrificing children (Lev. xviii:21), from Latin Moloch, from Greek Molokh, from Hebrew molekh, from melekh "king," altered by the Jews with the vowel points from basheth "shame" to express their horror of the worship.
Molotov cocktail (n.) Look up Molotov cocktail at Dictionary.com
1940, a term from Russo-Finnish War (used and satirically named by the Finns), from Molotov (from Russian molot "hammer") name taken by Vyacheslav Mikhailovich Skriabin (1890-1986), Soviet minister of foreign affairs 1939-1949.
molt (v.) Look up molt at Dictionary.com
also moult, mid-14c., mouten, of feathers, "to be shed," from Old English *mutian "to change" (in bemutian "to exchange"), from Latin mutare "to change" (see mutable). Transitive sense, of birds, "to shed feathers" is first attested 1520s. With parasitic -l-, late 16c., on model of fault, etc. Related: Molted, moulted; molting, moulting. As a noun from 1815.
molten (adj.) Look up molten at Dictionary.com
late 13c., from archaic past participle of Old English meltian, a class III strong verb (see melt (v.)).
moly (n.) Look up moly at Dictionary.com
1570s, fabulous magical herb with white flowers and black root, given by Hermes to Odysseus as protection against Circe's sorcery, of unknown origin.
molybdenum (n.) Look up molybdenum at Dictionary.com
metallic element, 1816, from molybdena, used generally for lead-like minerals, from Greek molybdos "lead," also "black graphite," related to Latin plumbum "lead" (see plumb (n.)), and like it probably borrowed from a lost Mediterranean language, perhaps Iberian. The element so called because of its resemblance to lead ore.
mom (n.) Look up mom at Dictionary.com
1867, American English, perhaps a shortening of mommy; also see mamma. Adjectival phrase mom and pop dates from 1951.
moment (n.) Look up moment at Dictionary.com
mid-14c., "very brief portion of time, instant," in moment of time, from Old French moment (12c.) "moment, minute; importance, weight, value" or directly from Latin momentum "movement, motion; moving power; alteration, change;" also "short time, instant" (also source of Spanish, Italian momento), contraction of *movimentum, from movere "to move" (see move (v.)). Some (but not OED) explain the sense evolution of the Latin word by notion of a particle so small it would just "move" the pointer of a scale, which led to the transferred sense of "minute time division." Sense of "importance, 'weight' " is attested in English from 1520s.

Phrase never a dull moment first recorded 1889 in Jerome K. Jerome's "Three Men in a Boat." Phrase moment of truth first recorded 1932 in Hemingway's "Death in the Afternoon," from Spanish el momento de la verdad, the final sword-thrust in a bull-fight.
momentarily (adv.) Look up momentarily at Dictionary.com
1650s, "for a moment," from momentary + -ly (2). Meaning "at any moment" is from 1928.
momentary (adj.) Look up momentary at Dictionary.com
"lasting a moment," mid-15c., from Latin momentarius "of brief duration," from momentum (see moment).
momently (adv.) Look up momently at Dictionary.com
1670s, "moment to moment," from moment + -ly (2). Meaning "at any moment" is from 1775.
momento (n.) Look up momento at Dictionary.com
a misspelling, or perhaps variant, of memento.
momentous (adj.) Look up momentous at Dictionary.com
1650s, from moment + -ous to carry the sense of "important" while momentary kept the meaning "of an instant of time." Related: Momentously; momentousness.
momentum (n.) Look up momentum at Dictionary.com
1690s, scientific use in mechanics, "quantity of motion of a moving body," from Latin momentum "movement, moving power" (see moment). Figurative use dates from 1782.
momma (n.) Look up momma at Dictionary.com
1884, American English variant of mamma (q.v.). As a biker's girlfriend or female passenger, from 1950s.
mommy (n.) Look up mommy at Dictionary.com
1844, U.S. variant of mamma. Variant spelling mommie attested by 1882. Mommy track first attested 1987. Related: Mommies; also see momma.
Momus (n.) Look up Momus at Dictionary.com
"humorously disagreeable person," 1560s, from Latin, from Greek Momos, nme of the god of ridicule and sarcasm (Greek momos, literally "blame, ridicule, disgrace," of unknown origin); also used in English as personification of fault-finding and captious criticism.
momzer (n.) Look up momzer at Dictionary.com
"contemptible person, moocher," 1560s, from Hebrew, literally "bastard" (used in Vulgate), but modern usage is a recent borrowing from Yiddish.
Mona Look up Mona at Dictionary.com
fem. proper name, from Irish Muadhnait, diminutive of muadh "noble."
Mona Lisa Look up Mona Lisa at Dictionary.com
from 1923, in reference to an enigmatic smile or expression like that in Leonardo DaVinci's painting. First attested in D.H. Lawrence.
monad (n.) Look up monad at Dictionary.com
"unity, arithmetical unit," 1610s, from Late Latin monas (genitive monadis), from Greek monas "unit," from monos "alone" (see mono-). In Leibnitz's philosophy, "an ultimate unit of being" (1748). Related: Monadic.
monarch (n.) Look up monarch at Dictionary.com
mid-15c., from Middle French monarque (14c.) or directly from Late Latin monarcha, from Greek monarkhes "one who rules alone" (see monarchy). As a type of large butterfly, from 1890.
monarchic (adj.) Look up monarchic at Dictionary.com
from Middle French monarchique, from Greek monarkhikos, from monarkhes (see monarch). Related: Monarchical (1570s).
monarchism (n.) Look up monarchism at Dictionary.com
from French monarchisme, from monarchie (see monarchy).
monarchist (n.) Look up monarchist at Dictionary.com
1640s, from monarchy + -ist. Related: Monarchistic.
monarchy (n.) Look up monarchy at Dictionary.com
"state ruled by monarchical government," mid-14c.; "rule by one person," late 14c.; from Old French monarchie "sovereignty, absolute power" (13c.), from Late Latin monarchia, from Greek monarkhia "absolute rule," literally "ruling of one," from monos "alone" (see mono-) + arkhein "to rule" (see archon).
monastery (n.) Look up monastery at Dictionary.com
c.1400, from Old French monastere "monastery" (14c.) and directly from Late Latin monasterium, from Ecclesiastical Greek monasterion "a monastery," from monazein "to live alone," from monos "alone" (see mono-). With suffix -terion "place for (doing something)." Originally applied to houses of any religious order, male or female.
monastic (adj.) Look up monastic at Dictionary.com
mid-15c., from Middle French monastique "monkish, monastic," or directly from Late Latin monasticus, from Ecclesiastical Greek monastikos "solitary, pertaining to a monk," from Greek monazein "to live alone" (see monastery). Related: Monastical (c.1400).
monasticism (n.) Look up monasticism at Dictionary.com
1795, from monastic + -ism.
Monday (n.) Look up Monday at Dictionary.com
second day of the week, Old English mondæg, monandæg "Monday," literally "day of the moon," from mona (genitive monan; see moon (n.)) + dæg (see day). Common Germanic (Old Norse manandagr, Old Frisian monendei, Dutch maandag, German Montag) loan-translation of Late Latin Lunæ dies, source of the day name in Romance languages (French lundi, Italian lunedi, Spanish lunes), itself a loan-translation of Greek selenes hemera. The name for this day in Slavic tongues generally means "day after Sunday."

Phrase Monday morning quarterback is attested from 1932, Monday being the first day back at work after the weekend, when school and college football games were played. Black Monday (mid-14c.) is the Monday after Easter day, though how it got its reputation for bad luck is a mystery. Saint Monday (1753) was "used with reference to the practice among workmen of being idle Monday, as a consequence of drunkenness on the Sunday" before [OED]. Clergymen, meanwhile, when indisposed complained of feeling Mondayish (1804) in reference to effects of Sunday's labors.