A greyish-white pyralid moth, Pleuroptya ruralis, whose larvae feed on nettles; (formerly also) †any of several moths resembling or related to this moth (obsolete).
Origin
Mid 18th century.
Definition of mother-of-pearl moth in US English:
mother-of-pearl moth
noun
A greyish-white pyralid moth, Pleuroptya ruralis, whose larvae feed on nettles; (formerly also) †any of several moths resembling or related to this moth (obsolete).