Rhodothamnus, rō-dō-tham′nus, n. a genus of small shrubs, the ground Cistus. [Gr. rhodon, rose, thamnos, bush.]
Rhodymenia, rō-di-mē′ni-a, n. a genus of marine algæ. [Gr. rhodon, rose, hymēn, membrane.]
Rhœadic, rē-ad′ik, adj. pertaining, to or derived from, the red poppy, Papaver Rhœas.—n. Rhœ′adine, a non-poisonous alkaloid found in the same. [Gr. rhoias, rhoiados, a poppy.]
Rhomb, romb, n. a quadrilateral figure having its sides equal but its angles not right angles: (crystal.) a rhombohedron: (Milt.) a material circle—also Rhom′bus.—adj. Rhom′bic.—ns. Rhombicosidodecahē′dron, a solid having sixty-two faces; Rhombicuboctahē′dron, a solid having twenty-six faces.—adjs. Rhom′biform, Rhom′boid, shaped like a rhomb.—Fresnel's rhomb, a rhomb of crown glass so cut that a ray of light entering one of its faces at right angles shall emerge at right angles at the opposite face, after undergoing two total reflections. [L. rhombus—Gr. rhombos—rhembein, to turn round and round.]
Rhombocœlia, rom-bō-sē′li-a, n. a dilatation of the spinal cord in the sacral region.—adj. Rhombocœ′lian. [Gr. rhombos, rhomb, koilia, a cavity.]
Rhombogen, rom′bō-jen, n. the infusoriform embryo of a nematoid worm.—adjs. Rhombogen′ic, Rhombog′enous. [Gr. rhombos, rhomb, genēs, producing.]
Rhombohedron, rom-bō-hē′dron, n. a solid bounded by six rhombic planes.—adj. Rhombohē′dral.—adv. Rhombohē′drally. [Gr. rhombos, rhomb, hedra, a base.]
Rhomboid, rom′boid, n. a figure of the form of a rhomb: a quadrilateral figure having only its opposite sides and angles equal.—adj. Rhomboid′al, having the shape of a rhomboid. [Gr. rhombos, rhomb, eidos, form.]
Rhomboideum, rom-boi′dē-um, n. (anat.) the ligament which unites the sternal end of the clavicle with the cartage of the first rib.
Rhombus. Same as Rhomb.