"an indefinitely large number; a crowd, many persons," Old English menigu, from a prehistoric Germanic word from the source of many (adj.). Compare Old Saxon menigi, Gothic managei "multitude, crowd," Old High German managi "large number, plurality," German Menge "multitude." The many "the multitude, the mass of people, the common herd" is attested from 1520s.
"being or consisting of a large number of units or individuals," Middle English mani, manige "indefinitely numerous, many a, much," from Old English monig, manig, from Proto-Germanic *managaz (source also of Old Saxon manag, Swedish mången, Old Frisian manich, Dutch menig, Old High German manag, German manch, Gothic manags), perhaps from a PIE *menegh- "copious" (source also of Old Church Slavonic munogu "much, many," Old Irish menicc, Welsh mynych "frequent," Old Irish magham "gift"), or perhaps a northern European substratum word also borrowed in Uralic (compare Finnish moni).
The pronunciation was altered by influence of any (see manifold). Middle English had comparative and superlative manier, maniest, also an adverbial form manygates "in many ways." Many honden maken liʒt werk is in "How the Good Wife Taught Her Daughter" (c. 1350).
The angels keep their ancient places—
Turn but a stone, and start a wing!
'Tis ye, 'tis your estrangèd faces,
That miss the many-splendored thing.
[from "In No Strange Land (The Kingdom of God is within you)" by Francis Thompson, 1907]
"of many kinds; numerous in kind or variety; diverse; exhibiting or embracing many points, features, or characteristics," Old English monigfald (Anglian), manigfeald (West Saxon), "various, varied in appearance, complicated; many times magnified; numerous, abundant," from manig (see many) + -feald (see -fold). A Proto-Germanic compound, *managafalþaz (source also of Old Frisian manichfald, Middle Dutch menichvout, German mannigfalt, Swedish mångfalt, Gothic managfalþs), perhaps a loan-translation of Latin multiplex (see multiply).
It retains the original pronunciation of many. Old English also had a verbal form, manigfealdian "to multiply, abound, increase, extend;" in modern times the verb meant "to make multiple copies of by a single operation." Related: Manifoldness.
1650s, of persons, "using many languages;" 1670s, of books, "containing many languages," perhaps via Medieval Latin polyglottus, from Greek polyglōttos "speaking many languages," literally "many-tongued," from polys "many" (from PIE root *pele- (1) "to fill") + glōtta, Attic variant of glōssa "language," literally "tongue" (see gloss (n.2)). As a noun from 1640s, "one who speaks or writes many languages." Related: Polyglottic; polyglottous.
"manifold, multiple, multiplicate," 1550s, from Latin multiplex "having many folds; many times as great in number; of many parts" (see multiply). As a noun, late 14c. in arithmetic, "a multiple."