Added 9 October 2026 reflectance noun Categories: Describing WordsRare Words noun ! Definition from WordNet 3.1, Princeton University. More about reflectance at Wordnik → Where our words come from → The fraction of radiant energy that is reflected from a surface. Related Words: reflectivityreflectionreflexionbrainstormingreflectancyabsorbtancephotoreflectancethermoreflectanceradiancereflectometry Back to today's word