1) Coefficient 2) Coefficient of reflection 3) Reflectance 4) Reflection factor 1) Echo 2) Reflectance 3) Reverberation 
Reflectivity or reflectance is the fraction of incident electromagnetic power that is reflected at an interface, in contrast to the reflection coefficient, which is the ratio of the reflected to incident electric field. == Reflectance == The reflectance or reflectivity is the square of the magnitude of the reflection coefficient. The reflection co...
reflectance of a layer of the material of such a thickness that there is no change of reflectance with increase in thickness unit : 1
the ability of a surface to reflect radiation incident upon it.
<physics> Fraction of incident radiant energy which is reflected by a given surface. (The power which is not reflected is either absorbed or transmitted.) ... (09 Oct 1997) ... 
Radar term referring to the ability of a radar target to return energy; used to estimate precipitation intensity and rainfall rates.
The ratio of the energy carried by a wave that is reflected from a surface to the energy of a wave incident on the surface. 
noun the ability to reflect beams or rays
A measure of the fraction of incident radiation falling on a surface that is turned back from it by reflection. Reflectivity also refers to the degree by which precipitation is able to reflect a radar beam.