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See Pasch and Easter.

Impervious to the rays of light; not transparent; as, an opaque substance.

The state or quality of being impervious to light; opacity. Dr. H. More.

Half opaque; only half transparent.

A silicate containing a large amount of cerium. It is usually black in color, opaque, and is related to epidote in form and composition.

An opaque or milk-white chalcedony, a variety of quartz; also, a similar variety of opal.

An opaque, compact variety of barite, or heavy spar. [Also written cauk.]

Free from opaqueness; transparent; bright; light; luminous; unclouded. The stream is so transparent, pure, and clear. Denham. Fair as the moon, clear as the sun. Canticles vi. 10.

Solid; gross; opaque. [Obs.] Holland.

To treat by pushing down or displacing the opaque lens with a needle; as, to couch a cataract. To couch a spear or lance, to lower to the position of attack; to place in rest. He stooped his head, and couched his spear, And spurred his steed to full career. Sir W. Scott. To couch malt, to spread malt on a floor. Mortim…

The operation of putting down or displacing the opaque lens in cataract.

A deviation of the rays of light toward the surface of an opaque body; inflection; diffraction.

crowded together; close; compact; thick; containing much matter in a small space; heavy; opaque; as, a dense crowd; a dense forest; a dense fog. All sorts of bodies, firm and fluid, dense and rare. Ray. To replace the cloudy barrier dense. Cowper.

The deflection and decomposition of light in passing by the edges of opaque bodies or through narrow slits, causing the appearance of parallel bands or fringes of prismatic colors, as by the action of a grating of fine lines or bars. Remarked by Grimaldi (1665), and referred by him to a property of light which he calle…

ing is seen from a distance through a large opening. By a combination of transparent and opaque painting, and of transmitted and reflected light, and by contrivances such as screens and shutters, much diversity of scenic effect is produced.

A preparation of opaque or body colors, in which the pigments are tempered or diluted with weak glue or size (cf. Tempera) instead of oil, usually for scene painting, or for walls and ceilings of rooms.

A glassy, opaque bead obtained by the blowpipe.

A method of painting with opaque colors, which have been ground in water and mingled with a preparation of gum; also, a picture thus painted.

Alternating transparent and opaque white rings which are seen outside the blastoderm, on the surface of the developing egg of the hen and other birds.

Having such a structure as to be diaphanous when moist, and opaque when dry.