N. reciprocalness, reciprocity, reciprocation, mutuality, correlation, interdependence, interrelation, connection, link, association, interchange, exchange, barter, reciprocator, reprocitist

V. reciprocate, alternate, interchange, exchange, counterchange

Adj. reciprocal, mutual, commutual, correlative, reciprocative, interrelated, closely related, alternate, interchangeable, interdependent, international, complemental, complementary

Adv. mutually, mutatis mutandis, vice versa, each other, one another, by turns, reciprocally

Phr. "happy in our mutual help"

N. number, symbol, numeral, figure, cipher, digit, # integer, counter, round number, formula, function, series, sum, difference, complement, subtrahend, product, multiplicand, multiplier, multiplicator, coefficient, multiple, dividend, divisor, factor, quotient, submultiple, fraction, rational number, surd, irrational number, transcendental number, mixed number, complex number, complex conjugate, numerator, denominator, decimal, circulating decimal, repetend, common measure, aliquot part, prime number, prime, relative prime, prime factor, prime pair, reciprocal, totient, binary number, octal number, hexadecimal number, permutation, combination, variation, election, ratio, proportion, comparison, progression, arithmetical progression, geometrical progression, harmonical progression, percentage, permilage, figurate numbers, pyramidal numbers, polygonal numbers, power, root, exponent, index, logarithm, antilogarithm, modulus, base, differential, integral, fluxion, fluent

Adj. numeral, complementary, divisible, aliquot, reciprocal, prime, relatively prime, fractional, decimal, figurate, incommensurable, proportional, exponential, logarithmic, logometric, differential, fluxional, integral, totitive, positive, negative, rational, irrational, surd, radical, real, complex, imaginary, finite, infinite, impossible

Adv. numerically, modulo