Diopsis, dī-op′sis, n. a genus of dipterous insects, of the fly family.
Dioptase, dī-op′tās, n. emerald copper ore.
Dioptrate, dī-op′trāt, adj. (entom.) divided transversely.
Dioptric, -al, dī-op′trik, -al, adj. pertaining to dioptrics.—ns. Diop′ter, an ancient form of theodolite: the index-arm of a graduated circle; Diop′trics, the part of optics which treats of the transmission of light from one medium to another.—Dioptric system, in lighthouses (as opposed to reflecting system), illumination from a central lamp whose rays are transmitted through a combination of lenses. [Gr. dia, through, opt-, as in opsesthai, to see, &c.]
Diorama, dī-ō-rä′ma, n. an exhibition of pictures, illuminated, and viewed through an opening in the wall of a darkened chamber.—adj. Dioram′ic. [Gr. dia, through, horama, a sight.]
Diorism, dī′ō-rizm, n. distinction, definition.—adjs. Dioris′tic, -al.—adv. Dioris′tically. [Gr. diorizein, to divide, dia, through, horos, a boundary.]
Diorite, dī′o-rīt, n. a crystalline granular igneous rock composed of feldspar and hornblende. [Gr. diorizein, to distinguish—dia, through, horos, a boundary.]
Diorthosis, dī-or-thō′sis, n. (surg.) the reduction of a dislocation, the correction of a deformity: a critical revision of a text.—adj. Diorthrot′ic. [Gr., dia, through, orthos, straight.]
Dioscorea, di-os-kōr′e-a, n. a genus of twining plants, containing the yams.—n. Dioscorā′ceæ, the order to which Dioscorea belongs.—adj. Dioscorā′ceous. [From the 1st-cent. Greek physician Dioscorides.]