What is the meaning of Glaucus?

Any member of the genus Glaucus of nudibranchiate mollusks, found in the warmer latitudes, swimming in the open sea, strikingly colored with blue and silvery white.

A desert lime (Citrus glauca), a thorny shrub species endemic to semi-arid regions of Australia.

shining

blue, green like aquamarine, often associated with silvery-green or dark green foliage, waters, sea and darkness (according to a gloss by Placidus, it describes the sea when it is whitened with currents)

synonym of caesius

blue-black

afflicted with an eye disease that prevents seeing

a bluish-grey colored fish of uncertain identity, perhaps the derbio

Source: wiktionary.org