Online Etymology Dictionary

meconium (n.): "fecal discharge from a newborn infant," 1706, from Latin meconium "excrement of a newborn child," literally "poppy juice," from Greek mekonion "poppy-juice, opium," diminutive of mekon "poppy" (perhaps cognate with Old Church Slavonic maku, German Mohn "poppy"). So called by classical physicians for its resemblance. Related: Meconial.
med (n.): colloquial abbreviation of medicine, 1942. With a capital M and short for Mediterranean, by 1948.
medal (n.): 1580s, from Middle French médaille (15c.), from Italian medaglia "a medal," according to OED from Vulgar Latin *metallea (moneta) "metal (coin)," from Latin metallum (see metal). The other theory [Klein, Barnhart, Watkins] is that medaglia originally meant "coin worth half a denarius," and is from Vulgar Latin *medalia, from Late Latin medialia "little halves," neuter plural of medialis "of the middle" (see medial (adj.)). Originally a trinket or charm; as a reward for merit, proficiency, etc., attested from 1751.
medal (v.): 1845, "stamped onto a medal," from medal (n.). From 1857 as "to award (someone or something) a medal;" intransitive sense is 20c. Related: Medaled; medalled; medaling; medalling.
medalist (n.): 1680s, "one skilled in medals," from medal (n.) + -ist. Meaning "medal-maker" is from 1756; that of "recipient of a medal" is from 1797.
medallion (n.): 1650s, from French médaillon (17c.), from Italian medaglione "large medal," augmentative of medaglia (see medal).
meddle (v.): early 14c., "to mingle, blend, mix," from Old North French medler (Old French mesler, 12c., Modern French mêler) "to mix, mingle, to meddle," from Vulgar Latin *misculare (source of Provençal mesclar, Spanish mezclar, Italian mescolare, meschiare), from Latin miscere "to mix" (see mix (v.)). From late 14c. as "busy oneself, be concerned with, engage in;" also disparagingly "interfere, be officious, make a nuisance of oneself" (the notion is of meddling too much). From mid-14c. to 1700, it also was a euphemism for "have sexual intercourse." Related: Meddled; meddling.
meddler (n.): late 14c., "practitioner," agent noun from meddle (v.). Meaning "one who interferes, a nuisance" is mid-15c.
meddlesome (adj.): 1610s, from meddle + -some (1). Earlier was medlous "quarrelsome, meddlesome" (mid-15c.). Related: Meddlesomely. Character name Meddlesome Mattie attested from 1814.
meddling (n.): "action of blending," mid-14c., from present participle of meddle (v.). Meaning "action of taking part, interference" is late 14c. As a past participle adjective, from 1520s. Related: Meddlingly.
Mede: inhabitant of ancient Media, late 14c., from Latin Medus, from Greek Medos "Mede," from the indigenous people-name Medes, said to be from the name of their first king (Medos).
Medea: famous sorceress, daughter of the king of Colchis, from Latin Medea, from Greek Medeia, literally "cunning," related to medos "counsel, plan, device, cunning," medein "to protect, rule over," from PIE root *med- "to measure, limit, consider" (see meditation).
medevac: 1966, U.S. military, formed from elements of medical evacuation.
media (n.): "newspapers, radio, TV, etc." 1927, perhaps abstracted from mass media (1923, a technical term in advertising), plural of medium, on notion of "intermediate agency," a sense found in that word in English from c. 1600.
mediaeval: see medieval.
medial (adj.): 1560s, "pertaining to a mathematical mean," from Late Latin medialis "of the middle," from Latin medius "in the middle, between; from the middle," as a noun (medium) "the middle;" from PIE *medhyo- "middle" (source also of Sanskrit madhyah, Avestan madiya- "middle," Greek mesos, Gothic midjis, Old English midd "middle," Old Church Slavonic medzu "between," Armenian mej "middle"); perhaps related to PIE root *me- "between." Meaning "occupying a middle position" is attested from 1721.
medial (n.): "a medial letter," 1776, from medial (adj.).
medially (adv.): 1804, from medial (adj.) + -ly (2).
median (adj.): 1590s, from Middle French médian (15c.) and directly from Latin medianus "of the middle," from medius "in the middle" (see medial (adj.)). Originally anatomical, of veins, arteries, nerves. Median strip "strip between lanes of traffic" is from 1954.
median (n.): "a median part," 1540s, from Latin medianus (see median (adj.)). Meaning "middle number of a series" is from 1883.
mediant (n.): "third note of the diatonic scale," 1753, from Italian mediante, from Late Latin mediantem (nominative medians) "dividing in the middle," present participle of mediare "to be in the middle" (see mediate). So called from being midway between the tonic and the dominant.
mediate (v.): 1540s, "divide in two equal parts," probably a back-formation from mediation or mediator, or else from Latin mediatus, past participle of mediare "to halve," later, "be in the middle," from Latin medius "middle" (see medial (adj.)). Meaning "act as a mediator" is from 1610s; that of "settle by mediation" is from 1560s. Related: Mediated, mediates, mediating.
mediation (n.): late 14c., from Medieval Latin mediationem (nominative mediatio) "a division in the middle," noun of action from past participle stem of mediare "to halve; to be in the middle" (see mediate). Related: Mediational.
mediator (n.): mid-14c., from Late Latin mediatorem (nominative mediator) "one who mediates," agent noun from past participle stem of mediare "to intervene, mediate," also "to be or divide in the middle" (see mediate). Originally applied to Christ, who in Christian theology "mediates" between God and man. Meaning "one who intervenes between two disputing parties" is first attested late 14c. Feminine form mediatrix (originally of the Virgin Mary) from c. 1400. Related: Mediatorial; mediatory.
medic (n.): 1650s, "physician, medical student," from Latin medicus "physician" (see medical (adj.)); modern sense of "serviceman in a military medical corps" first recorded 1925.
medicable (adj.): 1610s, from Latin medicabilis "curable," from medicare (see medical).
Medicaid: 1966, U.S. medical assistance program set up by Title XIX of the Social Security Act of 1965. See medical + aid (n.).
medical (adj.): 1640s, from French médical, from Late Latin medicalis "of a physician," from Latin medicus "physician, surgeon, medical man" (n.); "healing, madicinal" (adj.), from mederi "to heal, give medical attention to, cure," originally "know the best course for," from an early specialization of the PIE root *med- "to measure, limit, consider, advise, take appropriate measures" (source also of Greek medomai "be mindful of," medein "to rule;" Avestan vi-mad- "physician;" Latin meditari "think or reflect on, consider;" Irish miduir "judge;" Old English metan "to measure out"); also see meditation. The earlier adjective in English in this sense was medicinal. Related: Medically.
medical (n.): 1917, short for medical examination.
medicament (n.): mid-15c., "medical skill; a medicinal compound," from Middle French médicament (15c.), from Latin medicamentum "drug, remedy," literally "means of healing," from medicare "to heal, cure" (see medication).
Medicare: name for a state-run health insurance system, 1962, originally in a Canadian context, from medical + care (n.). U.S. use is from 1965.
medicaster (n.): "quack," c. 1600, from Latin *medicaster (source also of Italian medicastro, French médicastre, 16c.), from medicus (see medical (adj.)). The feminine form is medicastra. Compare also -aster.
medicate (v.): "to treat medicinally," 1620s, a back-formation from medication, or else from Late Latin medicatus, past participle of medicare. Related: Medicated; medicating. The earlier verb in English was simply medicin (late 14c.).
medication (n.): early 15c., "medical treatment of a disease or wound," from Middle French médication and directly from Latin medicationem (nominative medicatio) "healing, cure," from past participle stem of medicare, medicari "to medicate, heal, cure" (poetic and Late Latin) from medicus "physician, healing" (see medical (adj.)).
medicinal (adj.): late 14c., from Old French medicinal and directly from Latin medicinalis "pertaining to medicine," from medicina (see medicine). Related: Medicinally.
medicine (n.): c. 1200, "medical treatment, cure, remedy," also used figuratively, of spiritual remedies, from Old French medecine (Modern French médicine) "medicine, art of healing, cure, treatment, potion," from Latin medicina "the healing art, medicine; a remedy," also used figuratively, perhaps originally ars medicina "the medical art," from fem. of medicinus (adj.) "of a doctor," from medicus "a physician" (see medical); though OED finds evidence for this is wanting. Meaning "a medicinal potion or plaster" in English is mid-14c.

To take (one's) medicine "submit to something disagreeable" is first recorded 1865. North American Indian medicine-man "shaman" is first attested 1801, from American Indian adoption of the word medicine in sense of "magical influence." The U.S.-Canadian boundary they called Medicine Line (first attested 1910), because it conferred a kind of magic protection: punishment for crimes committed on one side of it could be avoided by crossing over to the other. Medicine show "traveling show meant to attract a crowd so patent medicine can be sold to them" is American English, 1938. Medicine ball "stuffed leather ball used for exercise" is from 1889.
It is called a "medicine ball" and it got that title from Prof. Roberts, now of Springfield, whose fame is widespread, and whose bright and peculiar dictionary of terms for his prescription department in physical culture is taught in every first-class conducted Y.M.C.A. gymnasium in America. Prof. Roberts calls it a "medicine ball" because playful exercise with it invigorates the body, promotes digestion, and restores and preserves one's health. ["Scientific American Supplement," March 16, 1889]
medico (n.): "medical practitioner," 1680s, from Spanish médico or Italian medico, from Latin medicus (see medical (adj.)).
medico-: used as a comb. form of Latin medicus (see medical (adj.)).
medico-legal (adj.): 1835, from medico- + legal.
medieval (adj.): 1827, "pertaining to or suggestive of the Middle Ages," coined in English from Latin medium "the middle" (see medium (n.)) + aevum "age" (see eon).
medievalism (n.): 1846, from medieval + -ism.
medievalist (n.): 1847, "proponent of medieval styles," from medieval + -ist. From 1882 as "one versed in the history of the Middle Ages."
medievally (adv.): 1844, from medieval + -ly (2).
medio-: word-forming element from comb. form of Latin medius "middle" (see medial (adj.)).
mediocre (adj.): 1580s, from Middle French médiocre (16c.), from Latin mediocris "of middling height or state, moderate, ordinary," figuratively "mediocre, mean, inferior," originally "halfway up a mountain," from medius "middle" (see medial (adj.)) + ocris "jagged mountain" (cognate with Greek okris "peak, point," Welsh ochr "corner, border," Latin acer "sharp;" see acrid). As a noun, "medicore thing or person," by 1834.
mediocritization (n.): 1917 (Will Durant), noun of state or action from mediocritize.
mediocritize (v.): 1854 (implied in mediocritizing); see mediocrity + -ize. Related: Mediocritized.
mediocrity (n.): early 15c., "moderation; intermediate state or amount," from Middle French médiocrité and directly from Latin mediocritatem (nominative mediocritas) "a middle state, middling condition, medium," from mediocris (see mediocre). Neutral at first; disparaging sense began to predominate from late 16c. The meaning "person of mediocre abilities or attainments" is from 1690s. Before the tinge of disparagement crept in, another name for the Golden Mean was golden mediocrity.
meditate (v.): 1580s, "to ponder," back-formation from meditation, or else from Latin meditatus, past participle of meditari (see meditation). Related: Meditated; meditating.
meditation (n.): c. 1200, "contemplation; devout preoccupation; devotions, prayer," from Old French meditacion "thought, reflection, study," and directly from Latin meditationem (nominative meditatio) "a thinking over, meditation," noun of action from past participle stem of meditari "to meditate, think over, reflect, consider," frequentative form from PIE root *med- "to measure, limit, consider, advise, take appropriate measures" (source also of Greek medesthai "think about," medon "ruler;" Latin modus "measure, manner," modestus "moderate," modernus "modern," mederi "to heal," medicus "physician;" Sanskrit midiur "I judge, estimate;" Welsh meddwl "mind, thinking;" Gothic miton, Old English metan "to measure;" also see medical).

Meaning "discourse on a subject" is early 14c.; meaning "act of meditating, continuous calm thought upon some subject" is from late 14c. The Latin verb also had stronger senses: "plan, devise, practice, rehearse, study."