Synonyms for Many:

adj.

countless (adjective)
untold, pile.
different (adjective)
various, diverse.
diverse (adjective)
multifarious.
frequent (adjective)
frequent, often, prevalent, repeated, habitual, common, profuse, usual, recurrent.
infinite (adjective)
numberless.
many (adjective)
divers, frequent, manifold, lousy with, no end of, countless, crowded, Multifold, sundry, numberless, bounteous, legion, innumerable, uncounted, several, umpteen, plentiful, teeming, prevalent, alive with, various, numerous, multifarious, multitudinous, multiplied, myriad.
much (adjective)
abundant, galore, everywhere, ample.
multifarious (adjective)
multiple.
numerous (adjective)
divers, thick with, bounteous, everywhere, sundry, of every description, profuse, manifold, innumerable, abundant, bursting out all over, a world of, multitudinous, crowded, Multifold, in heaps, multifarious, uncounted, untold, numerous, no end of, not a few, swarming, numberless, teeming, various, multiple, legion, alive with, plentiful, multiplex, diverse, no end to, Thronging, lousy with, ample, countless, multiplied, plenty.
plural (adjective)
any, numerous, some, plural, several.
populous (adjective)
swarming.
umpteen (adjective)
umteen, umpteen.
various (adjective)
divers, multiple.

n.

mass, pile, quantity, a lot/lots, much, abundance, a good/great deal of something, all manner of something, a load of/loads of something. human, folk, big, individual, the many, your fellow man/men, humanity, person, people, society, quite a few, myriad, man. many (noun)
mass, some, numerous, many an, many another, galore, umteen, plenty, many a, umpteen.

Other synonyms:

uncounted. myriad, much. countless
numberless.
numberless
innumerable.
uncounted
untold.