What is the meaning of Form_factor?

The ratio of the RMS value to the absolute mean of a sinusoidal wave (especially to that of an alternating current)

Any of several functions that describe the unknown internal state of a particle

The emissivity of a material

A function that describes the scattering power of an atom as function of the scattering angle

A factor describing the stress distribution of a body

The geometry of an object, especially in engineering design; configuration.

Source: wiktionary.org