Reflectance values express the percentage of light that is reflected back from a surface, the difference having been absorbed or transmitted by the surface.
Definition of AXIAL. 1. : of, relating to, or having the characteristics of an axis.
Definition of angle for English Language Learners. : 1  the difference between the direction of two lines or surfaces that come together : the space or shape formed when two lines or surfaces meet each other. â 2 used to describe a surface that is not level.