Synonyms for Multiple:

adj.

complex (adjective)
multiplex.
different (adjective)
various.
diverse (adjective)
multifarious.
numerous (adjective)
many.
repeated (adjective)
multiplied, repetitious.
various (adjective)
increased, added, multifarious, united, many-sided, many, versatile, compound, various, simple, multitudinous, varied, complicated.

n.

asymptomatic, catching, advanced, acute, congenital, benign, clinical, communicable, autoimmune, chronic. beauty parlor, bookstall, barbershop, bakeshop, book club, bookshop, antique shop, big-box store, beauty salon, bookstore. arithmetic progression, computation, constant, Arabic Numeral, common multiple, base, common factor. complementary, miscellaneous, balanced, integrated, heterogeneous, cohesive, jumbled, eclectic, graded. mathematics (noun)
cube, power, divisor, increment, modulus, radix, quotient, algorithm, differential calculus, subtrahend, trigonometry, logarithm, geometry, antilogarithm, coefficient, minuend, multiplicand, cube root, exponent, reciprocal, fraction, numerator, factor, root, quadratics, Multiplicator, algebra, square root, calculus, multiplier, dividend, arithmetic, denominator, formula, index, integral.
multiple (noun)
eightfold, quadruple, threefold, nonuple, fivefold, dual, octuple, tenfold, fourfold, duplex, quadruplex, aggregate, duple, sixfold, quadruplicate, denary, bigeminal, triple, fold, multiplex, triune, ninefold, quintuple, treble, manifold, sextuple, sevenfold, quaternary, twofold, binary, double, septuple, quaternate, ternary.

Other synonyms:

adj.
manifold.