Online Etymology Dictionary

miffy (adj.): "liable to 'take a miff,' " 1810, from miff (n.) + -y (2). Related: Miffiness.
MiG: in name of various Russian fighter planes, so called in honor of aircraft designers Mikoyan and (Russian i) Gurevitch.
might (v.): Old English mihte, meahte, originally the past tense of may (Old English magen "to be able"), thus "*may-ed." See may (v.). The first record of might-have-been is from 1848.
might (n.): Old English miht, earlier mæht "might, bodily strength, power, authority, ability," from Proto-Germanic *makhti- (source also of Old Norse mattr, Old Frisian, Middle Dutch, Dutch macht, Old High German maht, German Macht, Gothic mahts), Germanic suffixed form of PIE root *magh- (1) "be able, have power" (see may (v.)).
mightily (adv.): Old English mihtiglice; see mighty + -ly (2).
mightiness (n.): Old English mihtinesse; see mighty + -ness.
mighty (adj.): Old English mihtig, earlier mæhtig, from miht (see might (n.)). Similar formation in Old Frisian mechtig, Old Saxon mahtig, Dutch machtig, German mächtig. As an adverb, it is attested from c. 1300, though now considered colloquial.
mignon (adj.): "delicately formed," 1550s, French, literally "delicate, charming, pretty;" see minion. As a noun, "pretty child," from 1827.
migraine (n.): late 14c., megrim, from Old French migraigne (13c.), from vulgar pronunciation of Late Latin hemicrania "pain in one side of the head, headache," from Greek hemikrania, from hemi- "half" + kranion "skull" (see cranium). The Middle English form was re-spelled 1777 on the French model. Related: Migrainous.
migrant (adj.): 1670s, from Latin migrantem (nominative migrans), present participle of migrare "to remove, depart, to move from one place to another" (see migration).
migrant (n.): "person who migrates," 1760, from migrant (adj.).
migrate (v.): 1690s, from Latin migratus, past participle of migrare "to move from one place to another" (see migration). Related: Migrated; migrating.
migration (n.): 1610s, of persons, 1640s of animals, from Latin migrationem (nominative migratio) "a removal, change of abode, migration," noun of action from past participle stem of migrare "to move from one place to another," probably originally *migwros, from PIE *meigw- (source of Greek ameibein "to change"), from root *mei- (1) "to change, go, move" (see mutable). Related: Migrational.

That European birds migrate across the seas or to Asia was understood in the Middle Ages, but subsequently forgotten. Dr. Johnson held that swallows slept all winter in the beds of rivers, while the naturalist Morton (1703) stated that they migrated to the moon. As late as 1837 the "Kendal Mercury" "detailed the circumstance of a person having observed several Swallows emerging from Grasmere Lake, in the spring of that year, in the form of 'bell-shaped bubbles,' from each of which a Swallow burst forth ...."
migratory (adj.): 1753, from Latin migrat-, past participle stem of migrare "to movefrom one place to another" (see migration) + -ory.
mikado (n.): 1727, former title of the emperor of Japan, from mi "honorable" + kado "gate, portal." Similar to Sublime Porte, old title of the Ottoman emperor/government, and Pharaoh, which literally means "great house."
mil (n.): 1721, in per mil "per thousand," from Latin mille "thousand" (see million); compare percent. As a unit of length for diameter of wire, it is attested from 1891; as a unit of angular measure it is first recorded 1907.
Milan: city in northern Italy, Roman Mediolanum, from Gaulish medios "middle" + lanu "plain," in reference to its situation in the Po Valley. Related: Milanese.
milch (adj.): "giving milk," from Old English -milce "milking," from Proto-Germanic *melik- "milk" (see milk (n)).
mild (adj.): Old English milde "gentle, merciful," from Proto-Germanic *milthjaz- (source also of Old Norse mildr, Old Saxon mildi, Old Frisian milde, Middle Dutch milde, Dutch mild, Old High German milti, German milde "mild," Gothic mildiþa "kindness"), from PIE *meldh-, from root *mel- "soft," with derivatives referring to soft or softened materials (source also of Greek malthon "weakling," myle "mill;" Latin molere "to grind;" Old Irish meldach "tender;" Sanskrit mrdh "to neglect," also "to be moist"). Originally of persons and powers; of the weather from c. 1400, of disease from 1744. Also in Old English as an adverb, "mercifully, graciously."
Mild goes further than gentle in expressing softness of nature; it is chiefly a word of nature or character, while gentle is chiefly a word of action. [Century Dictionary]
mildew (n.): mid-13c., mildeu "honeydew, nectar," from Old English meledeaw "honeydew" (sticky stuff exuded by aphids), from Proto-Germanic compound of *melith "honey" (see Melissa) + *dawwaz "dew" (see dew). Similar formation in Old Saxon milidou, Dutch meeldauw, German Meltau "mildew."

First element in many cases assimilated to forms of meal (n.2) "ground grain." As a kind of fungus it is first recorded mid-14c., so called from its being sticky and originally growing in plants. As a verb from 1550s. Related: Mildewed.
mildly (adv.): Old English mildelice "graciously, affably, kindly;" see mild + -ly (2). Phrase to put it mildly is attested from 1929.
mildness (n.): Old English mildnes "mildness, mercy," from mild (adj.) + -ness.
Mildred: fem. proper name, Old English Mildðryð, from milde "mild" (see mild) + ðryð "power, strength." A popular name in the Middle Ages through fame of St. Mildred (obit c. 700), abbess, daughter of a Mercian king and a Kentish princess. Among the 10 most popular names for girls born in the U.S. between 1903 and 1926, it hasn't been in the top 1,000 since 1983.
mile (n.): Old English mil, from West Germanic *milja (source also of Middle Dutch mile, Dutch mijl, Old High German mila, German meile), from Latin milia "thousands," plural of mille "a thousand" (neuter plural was mistaken in Germanic as a fem. singular), of unknown origin.

The Latin word also is the source of French mille, Italian miglio, Spanish milla. The Scandinavian words (Old Norse mila, etc.) are from English. An ancient Roman mile was 1,000 double paces (one step with each foot), for about 4,860 feet, but there were many local variants and a modern statute mile is about 400 feet longer. In Germany, Holland, and Scandinavia in the Middle Ages, the Latin word was applied arbitrarily to the ancient Germanic rasta, a measure of from 3.25 to 6 English miles. Mile-a-minute (adj.) "very fast" is attested from 1957.
mileage (n.): 1754, "fixed rate per mile," from mile + -age. Meaning "a total number of miles" is from 1861.
milestone (n.): 1746, from mile + stone (n.).
MILF (n.): by 1999, acronym of Mother I'd Like to Fuck or some such thing.
Milicent: fem. proper name, earlier Malasintha, from shortened form of Old High German Amalswind, literally "strong in work," from amal "work" + *swind "strong" (related to Old English swið "strong," gesund "healthy").
milieu (n.): "surroundings," 1877, from French milieu, "middle, medium, mean," literally "middle place" (12c.), from mi "middle" (from Latin medius; see medial (adj.)) + lieu "place" (see lieu).
militancy (n.): 1640s, from militant + -cy.
militant (adj.): early 15c., "fighting, engaged in warfare," from Middle French militant "fighting," from Latin militantem (nominative militans), present participle of militare "serve as a soldier" (see militate), originally especially in Church militant. Related: Militantly.
militant (n.): "one engaged in war or strife," c. 1600, from militant (adj.); in a political sense, it is attested by 1907.
militarise (v.): chiefly British English spelling of militarize; for spelling, see -ize. Related: Militarised; Militarising.
militarism (n.): 1864, from French militarisme, from militaire "military" (see military).
militarist (n.): c. 1600, "a soldier," from military + -ist. As "one devoted to militarism" from 1884.
militaristic (adj.): 1883; see militarist + -ic.
militarize (v.): "turn to military use, give a military aspect to" (transitive), 1829, see military + -ize. Related: Militarized; militarizing.
military (adj.): mid-15c., from Middle French militaire (14c.), from Latin militaris "of soldiers or war, of military service, warlike," from miles (genitive militis) "soldier," of unknown origin, perhaps ultimately from Etruscan, or else meaning "one who marches in a troop," and thus connected to Sanskrit melah "assembly," Greek homilos "assembled crowd, throng." Related: Militarily. Old English had militisc, from Latin. Military-industrial complex coined 1961 in farewell speech of U.S. president Dwight D. Eisenhower.
military (n.): "soldiers generally," 1757, from military (adj.). Earlier, "a military man" (1736).
militate (v.): 1620s, "to serve as a soldier" (now rare), from Latin militatum, past participle of militare "serve as a soldier," from miles "soldier" (see military (adj.)). Sense developed via "conflict with," to "be evidence" for or against (1640s). Related: Militated; militating.
militia (n.): 1580s, "system of military discipline," from Latin militia "military service, warfare," from miles "soldier" (see military). Sense of "citizen army" (as distinct from professional soldiers) is first recorded 1690s, perhaps from a sense in French cognate milice. In U.S. history, "the whole body of men declared by law amenable to military service, without enlistment, whether armed and drilled or not" (1777).
militiaman (n.): 1780, from militia + man (n.).
milk (n.): Old English meoluc (West Saxon), milc (Anglian), from Proto-Germanic *meluks "milk" (source also of Old Norse mjolk, Old Frisian melok, Old Saxon miluk, Dutch melk, Old High German miluh, German Milch, Gothic miluks), from *melk- "to milk," from PIE root *melg- "to wipe, to rub off," also "to stroke; to milk," in reference to the hand motion involved in milking an animal (source also of Greek amelgein, Latin mulgere, Old Church Slavonic mlesti, Lithuanian melžu "to milk," Old Irish melg "milk," Sanskrit marjati "wipes off"). Old Church Slavonic noun meleko (Russian moloko, Czech mleko) is considered to be adopted from Germanic.

Of milk-like plant juices from late 14c. Milk chocolate is first recorded 1723; milk shake is first recorded 1889, for a variety of creations, but the modern version is only from the 1930s. Milk tooth (1727) uses the word in its figurative sense "period of infancy," attested from 17c. To cry over spilt milk is first attested 1836 in writing of Canadian humorist Thomas C. Haliburton. Milk and honey is from the Old Testament phrase describing the richness of the Promised Land (Num. xvi:13, Old English meolc and hunie). Milk of human kindness is from "Macbeth" (1605).
milk (v.): Old English melcan, milcian, meolcian "to milk, give milk, suckle," from Proto-Germanic *melk- "to milk" (source also of Dutch melken, Old High German melchan, German melken), from PIE root *melg- (see milk (n.)). Figurative sense of "exploit for profit" is first found 1520s. Related: Milked; milking.
milk of magnesia (n.): 1880, proprietary name for white suspension of magnesium hydroxide in water, taken as an antacid, invented by U.S. chemist Charles Henry Phillips. Herbal or culinary preparations resembling milk had been similarly named (for example milk of almond) since early 15c.
milkmaid (n.): 1550s, from milk (n.) + maid.
milkman (n.): 1580s, from milk (n.) + man (n.).
milksop (n.): "effeminate spiritless man," late 14c., attested as a (fictional) surname mid-13c.; also applied in Middle English to the infant Christ. Literal sense "piece of bread soaked in milk" attested late 15c.; see milk (n.) + sop (n.).
milktoast (n.): also milk-toast, "toast softened in milk," 1831, from milk (n.) + toast (n.). Figurative of softness or innocence by 1859.
milkweed (n.): 1590s, from milk (n.) + weed (n.); used in reference to various plants whose juice resembles milk.