The Collaborative International Dictionary
Glaucous \Glau"cous\ (gl[add]"k[u^]s), a. [L. glaucus, Gr. glayko`s.]
Of a sea-green color; of a dull green passing into grayish blue.
--Lindley.(Bot.) Covered with a fine bloom or fine white powder easily rubbed off, as that on a blue plum, or on a cabbage leaf.
--Gray.
Douglas Harper's Etymology Dictionary
"bluish-green, gray," 1670s, from Latin glaucus "bluish-green," of uncertain origin; used in Homer of the sea as "gleaming, silvery" (apparently without a color connotation); used by later writers with a sense of "bluish-green, gray," of olive leaves and eyes. Homer's glauk-opis Athene probably originally was a "bright-eyed," not a "gray-eyed" goddess. Greek for "owl" was glaux from its bright, staring eyes.
Wiktionary
a. 1 Of a pale green colour with a bluish-grey tinge, especially when covered with a powdery residue. 2 (context botany English) Covered with a bloom or a pale powdery covering, regardless of colour.
WordNet
adj. having a frosted look from a powdery coating, as on plants; "glaucous stems"; "glaucous plums"; "glaucous grapes"
Wikipedia
Glaucous (from the Latin glaucus, meaning "bluish-grey or green", from the Greek glaukós) is used to describe the pale grey or bluish-green appearance of the surfaces of some plants, as well as in the names of birds, such as the glaucous gull (Larus hyperboreus), glaucous-winged gull (Larus glaucescens), glaucous macaw (Anodorhynchus glaucus), and glaucous tanager (Thraupis glaucocolpa).
The term glaucous is also used botanically as an adjective to mean "covered with a greyish, bluish, or whitish waxy coating or bloom that is easily rubbed off" (e.g. glaucous leaves).
The first recorded use of glaucous as a color name in English was in the year 1671.
Usage examples of "glaucous".
Thunderstorms came frequently out of the east, enormous cloudscapes with hearts of livid magenta and glaucous green.
Timothy Tox, Pennsylvaniad Through July they continue North, thro' swamps, snakes, godawful humidity, thunder-gusts at night, trees so thick that even with thirty axmen, each chain's length seems won with Labor incommensurate, waking each glaucous Dawn into sweat and stillness, to struggle another Day, with no confidence that at the correct Distance, they will pass anywhere near the Tangent Point, much less touch it exactly.
What strange voyages, downward through its glaucous depths, upwards to its boiling and frothing surface, wafted by tides, driven by tempests, disparted by rude agencies.
As at Walden, in sultry dogday weather, looking down through the woods on some of its bays which are not so deep but that the reflection from the bottom tinges them, its waters are of a misty bluish-green or glaucous color.
It has a large, fleshy rhizome, and the alternate, lanceolate leaves are blades from 1 to 2 1/2 feet long, smooth and dark green above, pale, glaucous green and finely silky beneath.
Twice that afternoon Stephen was called on deck, once to see a troop of grampuses, and once to be shown a startling change in the sea, which from a turbid, undistinguished glaucous hue had become clear, glass clear, and of that aquamarine colour which had come back to his mind when he spoke of Leopard's iceberg: the rest of the time he spent in the cabin, speaking Malay with Ahmed or listening to him read from Fox's text.