Rheostat, rē′o-stat, n. the name given by Wheatstone to an instrument for varying an electric resistance between given limits.—adj. Rheostat′ic.—n. Rheostat′ics, the statics of fluids. [Gr. rhein, to flow, statos, verbal adj. of histanai, to stand.]
Rheotome, rē′ō-tōm, n. a means by which an electric current can be periodically interrupted. [Gr. rhein, to flow, temnein, to cut.]
Rheotrope, rē′ō-trōp, n. an instrument for periodically changing the direction of an electric current.—n. Rheot′rōpism, the effect of a current of water upon the direction of plant growth. [Gr. rhein, to flow, trepein, to turn.]
Rhesus, rē′sus, n. the boonder, one of the most widely distributed Indian monkeys, much venerated by the natives: (entom.) a genus of coleopterous insects.—adj. Rhē′sian. [Gr.]
Rhetoric, ret′or-ik, n. the theory and practice of eloquence, whether spoken or written, the whole art of using language so as to persuade others: the art of speaking with propriety, elegance, and force: artificial oratory: declamation.—adj. Rhetor′ical, pertaining to rhetoric: oratorical.—adv. Rhetor′ically.—v.i. Rhetor′icāte (obs.), to act the orator.—ns. Rhetoricā′tion (obs.); Rhetori′cian, one who teaches the art of rhetoric: an orator.—v.i. Rhet′orise, to play the orator. [Fr.,—L. rhetorica (ars)—Gr. rhētorikē (technē), the rhetorical (art)—rhētōr, a public speaker—erein, to speak.]
Rheum, rōōm, n. the mucous discharge from the lungs or nostrils caused by cold: (obs.) spleen, choler: a genus of apetalous plants.—n. Rheumat′ic, one who suffers from rheumatism: (pl.) rheumatic pains (coll.).—adjs. Rheumat′ic, -al, pertaining to or affected with rheumatism: choleric.—n. Rheum′atism, a name still used somewhat loosely, but applying specially to an acute febrile disease, with swelling and pain in and around the larger joints.—adjs. Rheumatis′mal; Rheum′atoid, resembling rheumatism.—n. Rheumophthal′mia, rheumatic ophthalmia.—adj. Rheum′y, full of or causing rheum. [L.,—Gr. rheuma—rhein, to flow.]
Rhexia, rek′si-a, n. a genus of polypetalous plants, native to North America, of the tribe Rhexieæ (rek-sī′ē-ē). [L.,—Gr. rhēxis—rhēgnynai, to break.]
Rhigolene, rig′ō-lēn, n. a volatile product of petroleum distillation. [Gr. rhigos, cold, elaion, oil.]
Rhinacanthus, rī-na-kan′thus, n. a genus of gamopetalous plants in tropical Africa, India, &c. [Gr. rhis, rhinos, nose, akanthos, acanthus.]
Rhinæ, rī′nē, n.pl. one of the main divisions of sharks. [L.,—Gr. rhinē, a file.]