modulus

A quantity that expresses the degree to which a substance possesses a property, such as elasticity.

The square root of the product of a complex number and its complex conjugate.

A natural number used as a specified divisor in modular arithmetic.

The number by which a logarithm in one system must be multiplied to obtain the corresponding logarithm in another system.

In mathematics, a real positive number that serves as measure or parameter of a function or effect. Represented by M. or μ.

In physics, the measure of an effect under conditions whose measure is unity. Thus, a physical modulus is not a number, but a physical quantity.

[capitalized] In conchology, a genus of gastropods, referred to the Littorinidæ or periwinkles, or made type of the family Modulidæ. The shell is depressed and trochiform, with a deeply cut columellar tooth and many-whorled operculum.

then the modulus of transformation is

A quantity or coefficient, or constant, which expresses the measure of some specified force, property, or quality, as of elasticity, strength, efficiency, etc.; a parameter.