the hard, pearly internal layer of certain marine shells, as of the pearl oyster or abalone, which is used in the arts, in making pearl buttons, etc.
Origin of mother-of-pearltranslated, translation of Medieval Latin mater perlarum: origin, originally applied to the marine animal, later to the shell
of the mother-of-pearl
The pearly internal layer of certain mollusk shells, used to make decorative objects. Also called nacre.