Equiluminant refers to two or more objects or surfaces that appear to have the same level of brightness or luminescence. It is a term often used in the field of color vision research. Synonyms for equiluminant include isoluminant, equichromatic, and iso-brightness. These terms all refer to the same phenomenon of equal luminance or brightness. Additionally, the term equiluminous is sometimes used as an adjective to describe objects or surfaces that have the same luminance. These synonyms are important to know and understand in fields such as graphic design and color theory, where precise language is necessary for accurate communication about color and light.