modulus

noun pl. moduli

1. Math.
   1. the absolute value of a complex number, computed by adding the squares of each part and taking the positive square root of the sum (i.e.: the modulus of a + bi is )
   2. a quantity which gives the same remainders when it is the divisor of two quantities
   3. the factor by which a logarithm to one base is multiplied to change it to a logarithm to another base
2. Physics a quantity expressing the response of a sample of material to an external stimulus, as mechanical stress: the response is usually expressed as a fractional change in the physical quantity being affected