Medical Definition of metamer
1: a chemical compound that is metameric with one or more others
2: either of two colors of different spectral composition that appear identical to the eye of a single observer under some lighting conditions but different under others or that under constant lighting conditions appear identical to some observers and different to others
Seen and Heard
What made you want to look up metamer? Please tell us where you read or heard it (including the quote, if possible).