Online Etymology Dictionary

morphodite (n.): 1839, colloquial mangling of hermaphrodite. An earlier mangling was mophrodite (1706); also see dyke.
morphogenesis (n.): 1863 in biology; 1958 in geology; from morpho- + -genesis "birth, origin, creation." Related: Morphogenetic.
morphology (n.): 1824 in biology (from German Morphologie, 1817); 1869 in philology; from morpho- + -logy. Related: Morphological; morphologist. Related: Morphologist.
morphosis (n.): "mode of formation," Modern Latin, from Greek morphosis "a forming, shaping," from morphe "form, shape; outward appearance" (see Morpheus).
Morris: surname and masc. proper name, in some cases representing Maurice (common form Morice, or a nickname, Moorish, for onme who is swarthy. As a style of furniture, wallpaper, etc., 1880, in reference to poet and craftsman William Morris (1834-1896).
morris dance (n.): mid-15c., moreys daunce "Moorish dance," from Flemish mooriske dans, from Old French morois "Moorish, Arab, black," from More "Moor" (see Moor). Unknown why the English dance was called this, unless in reference to fantastic dancing or costumes (compare Italian Moresco, a related dance, literally "Moorish;" German moriskentanz, French moresque).
morrow (n.): mid-13c., morewe-; c. 1300, morwe, shortened variation of morewen "morrow" (see morn).
Morse code (n.): 1867, earlier Morse key (1858), in honor of Samuel F.B. Morse (1791-1872), U.S. inventor who produced a system of telegraphic communication 1836. He invented both the recording telegraph and the alphabet of dots and dashes.
morsel (n.): late 13c., "a bite, mouthful; small piece, fragment," from Old French morsel (Modern French morceau) "small bite, portion, helping," diminutive of mors "a bite," from Latin morsus "biting, a bite," neuter past participle of mordere "to bite" (see mordant).
mort (n.1): "girl, woman" (especially one of loose morals), 1560s, canting jargon, of unknown origin.
mort (n.2): note sounded on a horn at the death of the quarry, c. 1500, from French mort "dead," from Latin mortem (source of Spanish muerte, Italian morte), accusative of mors "death" (see mortal (adj.)). Or from French mort "dead," from Vulgar Latin *mortus, from Latin mortuus.
mortal (adj.): mid-14c., "deadly," also "doomed to die," from Old French mortel "destined to die; deserving of death," from Latin mortalis "subject to death, mortal, of a mortal, human," from mors (genitive mortis) "death," from PIE base *mer- "to die," with derivatives referring to death and human beings" (source also of Sanskrit mrtih "death," martah "mortal man;" Avestan miryeite "dies," Old Persian martiya- "man;" Armenian meranim "die;" Latin mori "to die;" Lithuanian mirtis "mortal man;" Greek brotos "mortal" (hence ambrotos "immortal"); Old Church Slavonic mrutvu "dead;" Old Irish marb, Welsh marw "died;" Old English morþ "murder"). The most widespread Indo-European root for "to die," forming the common word for it except in Greek and Germanic. Watkins says it is "possibly" the same as PIE *mer- "rub, pound, wear away" (see morbid).
mortal (n.): "mortal thing or substance," 1520s, from mortal (adj.). Latin mortalis also was used as a noun, "a man, mortal, human being."
mortality (n.): mid-14c., "condition of being mortal," from Old French mortalite "massacre, slaughter; fatal illness; poverty; destruction" (12c.), from Latin mortalitem (nominative mortalitas) "state of being mortal; subjection to death," from mortalis (see mortal (adj.)). Meaning "widespread death" is from c. 1400; meaning "number of deaths from some cause or in a given period" is from 1640s.
mortally (adv.): late 14c., "to the death; resulting in death," also "bitterly, intensely," from mortal (adj.) + -ly (2).
mortar (n.1): "mixture of cement," late 13c., from Old French mortier "builder's mortar, plaster; bowl for mixing" (13c.), from Latin mortarium "mortar," also "crushed drugs," probably the same word as mortarium "bowl for mixing or pounding" (see mortar (n.2)). Dutch mortel, German Mörtel are from Latin or French.
mortar (n.2): "bowl for pounding," c. 1300, from Old French mortier "bowl; builder's mortar," from Latin mortarium "bowl for mixing or pounding," also "material prepared in it," of unknown origin and impossible now to determine which sense was original (Watkins says probably from PIE root *mer- "to rub away, harm;" see morbid). Late Old English had mortere, from the same Latin source, which might also be a source of the modern word. German Mörser also is from Latin.
mortar (n.3): "short cannon" fired at a high angle and meant to secure a vertical fall of the projectile, 1550s, originally mortar-piece, from Middle French mortier "short cannon," in Old French, "bowl for mixing or pounding" (see mortar (n.2)). So called for its shape.
mortarboard (n.): also mortar-board, "academic cap," 1854, probably from mortar (1) + board (n.1); so called because it resembles a mason's square board for carrying mortar. Earlier it was called a mortar cap (1680s) or simply morter (c. 1600), from French mortier.
mortgage (n.): late 14c., morgage, "conveyance of property as security for a loan or agreement," from Old French morgage (13c.), mort gaige, literally "dead pledge" (replaced in modern French by hypothèque), from mort "dead" (see mortal (adj.)) + gage "pledge" (see wage (n.)). So called because the deal dies either when the debt is paid or when payment fails. Old French mort is from Vulgar Latin *mortus "dead," from Latin mortuus, past participle of mori "to die" (see mortal (adj.)). The -t- restored in English based on Latin.
mortgage (v.): late 15c., from mortgage (n.). Related: Mortgaged; mortgaging.
mortgagee (n.): 1580s, from mortgage (v.) + -ee.
mortgagor (n.): 1580s, agent noun in Latin form from mortgage (v.). Native form mortgager attested from 1630s.
mortician (n.): 1895, American English, coined from mortuary + -ician, as in physician.
An undertaker will no longer be known as an "undertaker and embalmer." In the future he will be known as the "mortician." This was decided on at the second day's meeting of the Funeral Directors' Association of Kentucky, which was held in Louisville. ["The Medical Herald," July 1895]
mortification (n.): late 14c., "mortifying the flesh, suppression of bodily desires," from Late Latin mortificationem (nominative mortificatio) "a killing, putting to death," from past participle stem of mortificare (see mortify). Sense of "feeling of humiliation" first recorded 1640s.
mortified (adj.): "deeply humiliated," 1717, past participle adjective from mortify.
mortify (v.): late 14c., "to kill," from Old French mortefiier "destroy, overwhelm, punish," from Late Latin mortificare "cause death, kill, put to death," literally "make dead," from mortificus "producing death," from Latin mors (genitive mortis) "death" (see mortal (adj.)) + root of facere "to make" (see factitious). Religious sense of "to subdue the flesh by abstinence and discipline" first attested early 15c. Sense of "humiliate" first recorded 1690s (compare mortification). Related: Mortified; mortifying.
Mortimer: masc. proper name and surname, from Mortemer, name of a place in Normandy.
mortise (n.): c. 1400, "hole or groove in which something is fitted to form a joint," from Old French mortaise (13c.), possibly from Arabic murtazz "fastened," past participle of razza "cut a mortise in." Compare Spanish mortaja.
mortise (v.): mid-15c., from mortise (n.). Related: Mortised; mortising.
mortmain (n.): "inalienable ownership," mid-15c., from Anglo-French morte mayn, Old French mortemain, literally "dead hand," from Medieval Latin mortua manus; see mortal (adj.) + manual (adj.). Probably a metaphorical expression.
Morton: surname, from the many Mortons on the map of England, literally "moor or marsh settlement." Morton's Fork (1759) is in reference to John Morton (c. 1420-1500), archbishop of Canterbury, who levied forced loans under Henry VII by arguing the obviously rich could afford to pay and the obviously poor clearly were living frugally and thus had savings and could pay, too.
mortuary (n.): early 14c., from Anglo-French mortuarie "gift to a parish priest from a deceased parishioner," from Medieval Latin mortuarium, noun use of neuter of Late Latin adjective mortuarius "pertaining to the dead," from Latin mortuus, past participle of mori "to die" (see mortal (adj.)). Meaning "place where bodies are kept temporarily" first recorded 1865, a euphemism for earlier deadhouse.
mortuary (adj.): 1510s, "pertaining to death," from Late Latin mortuarius "of the dead," from Latin mortuus "dead" (see mortuary (n.)).
Morus (n.): genus of mulberry trees, from Latin morus "mulberry tree."
mosaic (n.): c. 1400, from Old French mosaicq "mosaic work," from Italian mosaico, from Medieval Latin musaicum "mosaic work, work of the Muses," noun use of neuter of musaicus "of the Muses," from Latin Musa (see muse). Medieval mosaics were often dedicated to the Muses. The word formed in Medieval Latin as though from Greek, but the (late) Greek word for "mosaic work" was mouseion (Klein says this sense was borrowed from Latin). Figurative use is from 1640s. As an adjective in English from 1580s. Related: Mosaicist.
Mosaic (adj.): "pertaining to Moses," 1660s (earlier Mosaical, 1560s), from Modern Latin Mosaicus, from Moses.
mosasaurus (n.): marine dinosaur, 1830, from Latin Mosa "the river Meuse" + -saurus. the fossils of the ancient reptile were first discovered 1780 near Maastricht, on the Meuse.
Moscow: Russian capital, named for Moskva River, of unknown origin. Moscow mule, vodka cocktail, attested from 1950.
Moselle: river in Western Europe, Latin Mosella, literally "Little Meuse," in reference to the longer River Meuse (Latin Mosa), into which it flows. From 1680s as "wine from the valley of the river Moselle.
Moses: masc. proper name, name of Hebrew prophet and lawgiver, from Latin, from Greek Mouses, from Hebrew Mosheh, of unknown origin.
Most scholars see in it the Hebraization of Egyptian mes, mesu 'child, son,' which is often used in theophorous names. According to this derivation the words of Pharaoh's daughter in Ex. 2:10, 'For out of the water I drew him' are not the explanation of the Hebrew name Mosheh, but express the idea that the Egyptian name given by Pharaoh's daughter resembles in sound, and therefore, reminds us of, the Hebrew verb mashah 'he drew out,' which is suggestive of the words spoken by Pharaoh's daughter. [Dr. Ernest Klein, "A Comprehensive Etymological Dictionary of the English Language"]
As an expletive or oath, 1840.
mosey (v.): 1829, American English slang, of unknown origin, perhaps related to British dialectal mose about "go around in a dull, stupid way." Or perhaps from Spanish vamos (see vamoose). Related: Moseyed; moseying.
mosh (v.): "to dance (with a certain amount of violence) to metal music in a tightly packed arena," 1987, perhaps a variant of mash. Related: Mosh pit.
Moslem: see Muslim.
mosque (n.): 1717, earlier moseak (c. 1400), also mosquee (16c.), probably in part from Middle French mosquée, from Italian moschea, earlier moscheta, from Spanish mesquita (modern mezquita), from Arabic masjid "temple, place of worship," from sajada "he worshipped" + prefix ma- denoting "place." Mangled in Middle English as muskey, moseache, etc.
mosquito (n.): 1580s, from Spanish mosquito "little gnat," diminutive of mosca "fly," from Latin musca "fly," from PIE root *mu- "gnat, fly," imitative of insect buzzing (compare Sanskrit maksa-, Greek myia, Old English mycg, Modern English midge, Old Church Slavonic mucha), perhaps imitative of the sound of humming insects.
moss (n.): Old English meos "moss," related to mos "bog," from Proto-Germanic *musan (source also of Old High German mios, Danish mos, German Moos), also in part from Old Norse mosi "moss, bog," and Medieval Latin mossa "moss," from the same Germanic source, from PIE *meus- "damp," with derivatives referring to swamps and swamp vegetation (source also of Latin muscus "moss," Lithuanian musai "mold, mildew," Old Church Slavonic muchu "moss").
Selden Moseþ þe Marbelston þat men ofte treden. ["Piers Plowman," 1362]
All the Germanic languages have the word in both senses, which is natural because moss is the characteristic plant of boggy places. It is impossible to say which sense is original. Scott (1805) revived 17c. moss-trooper "freebooter infesting Scottish border marshes."
mossback (n.): "conservative," 1874, especially of poor whites from Carolina, originally (1872) in reference to those who hid out to avoid service in the Confederate army (and would have stayed out till the moss grew on their backs); from moss + back (n.).
mossy (adj.): 1560s, from moss + -y (2).
most (adj.): Old English mast "greatest number, amount, extent," earlier mæst, from Proto-Germanic *maistaz (source also of Old Saxon mest, Old Frisian mast, Old Norse mestr, Dutch meest, German meist, Gothic maists "most"), superlative form of Proto-Germanic *maiz, root of Old English ma, mara (see more). Used in Old English as superlative of micel "great, large" (see mickle). Vowel influenced by more. Original sense of "greatest" survives in phrase for the most part (c. 1400). Slang meaning "the best, extremely good" is attested from 1953. Also used as an adverb in Old English. Phrase make the most of (something) is by 1520s. Related: Mostly. Double superlative mostest is 1885, from U.S. Southern and African-American vernacular.