Definitions

1. adjective

having a smooth, iridescent, or mother-of-pearl-like appearance or quality

“The nacreous sheen on the butterfly’s wings glimmered in the sunlight.”

2. adjective

resembling or having the quality of nacre, especially in being smooth, shiny, or iridescent

“The nacreous film that formed on the surface of the lake created a beautiful optical effect.”

3. noun

a substance having a smooth, iridescent, or mother-of-pearl-like appearance or quality

“The nacreous material was used in the design of the new jewelry collection.”