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.
Other directional terms. Several other terms are also used to describe location. These terms are not used to form the fixed axes. Terms include: Axial (from Latin axis, meaning 'axle'): around the central axis of the organism or the extremity.