mother-of-pearl

Meanings

1. The hard pearly inner layer of certain mollusk shells; nacre.
2. A butterfly of the genus Salamis.

1. Made from or looking like mother-of-pearl; iridescent or pearly.

Etymology

Calque of Latin māter perlārum, with the first element perhaps connected in popular imagination with obsolete mother (“dregs”). Possibly referring to the fact that the nacre-lined shells are the belly (“mother”) in which pearls are produced.