Opalescently

Part of speech: adverb

Definitions

1. Exhibiting a shimmering, rainbow-like quality that resembles the light-play of opals
2. Possessing an iridescent characteristic that displays a spectrum of colors reminiscent of an opal's surface
3. In a way that shows a changing play of colors like those found in an opal's surface

Etymology: "Opalescently" is simply "opalescent" with the adverbial ending "-ly" attached, so it describes something happening in the manner of an opalescent surface, one that shows milky, shifting colors as the light or viewing angle changes. The adverb's meaning follows directly from the adjective: the play of color is the whole point. The adjective "opalescent" is itself built on "opal," the gemstone, with the suffix "-escent," which carries the sense of beginning to show a quality or becoming like something. An opalescent surface is therefore one that is becoming opal-like, displaying the soft, milky iridescence that gives the gem its character.