c. 1300, "hand-to-hand combat, war, battle," a sense now obsolete, from Old French medlee, variant of meslee, from mesler "to mix, mingle, meddle" (see meddle). From mid-14c. as "cloth made of wools dyed and mingled before being spun," whether of one color or many, but especially pied cloth. The general meaning "a combination, a mixture" is from c. 1400; that of "musical composition or entertainment consisting of diverse parts from different sources" is from 1620s.
"confused conflict among many persons," 1640s, from French mêlée, from Old French meslee "brawl, confused fight; mixture, blend" (12c.), noun use of fem. past participle of mesler "to mix, mingle" (see meddle). See also medley. Borrowed in Middle English as melle but it was lost and then reborrowed 17c.
also *meig-, Proto-Indo-European root meaning "to mix."
It forms all or part of: admix; admixture; immiscible; mash; meddle; medley; melange; melee; mestizo; metis; miscegenation; miscellaneous; miscible; mix; mixo-; mixture; mustang; pell-mell; promiscuous.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit misrah "mixed;" Greek misgein, mignynai "to mix, mix up, mingle; to join, bring together; join (battle); make acquainted with;" Old Church Slavonic mešo, mesiti "to mix," Russian meshat, Lithuanian maišau, maišyti "to mix, mingle," Welsh mysgu "to mix."
savory medley dish of Iberian origin, 1640s, from Spanish olla, Portuguese olha, both from Vulgar Latin *olla "pot, jar." With the common mistake of -o for -a in English words from Spanish. The sense was transferred from the pot to what went into it. Extended sense of "any mixture or medley, a collection of various pieces" is from 1640s in English.
"a mixture, a medley," usually "an uncombined mingling on elements, objects, or individuals," 1650s, from French mélange (15c.), from mêler "to mix, mingle," from Old French mesler "to mix, meddle, mingle" (see meddle).
"hodgepodge, a confused mix," 1630s, from Latin farrago "medley, mixed fodder, mix of grains for animal feed," from far "grain" (see farina).