: the reflective quality or power of a surface or material
… conducting "reflectivity tests" to see whether Saudi sand when viewed through the goggles creates a sparkling effect that disorients pilots and causes them to send their helicopters careening to the ground.Newsweek
… there are many examples of luster-decorated ceramics, in which Islamic potters emulated the reflectivity of metalwork by applying metal oxides to white-glazed vessels … Roberta Smith
The warming at the surface could be expected to melt snow and ice, reducing the earth's albedo, or reflectivity. Roger Revelle