Orbilius, or-bil′i-us, n. a flogging schoolmaster—from Horace's master.

Orbit, or′bit, n. the path in which one of the heavenly bodies, as a planet, moves round another, as the sun: the hollow in the bone in which the eyeball rests—also Or′bita: the skin round the eye.—adjs. Or′bital, Or′bitary. [L. orbitaorbis, a ring.]

Orc, ork, n. any whale, the grampus. [L. orca.]

Orcadian, or-kā′di-an, adj. of or pertaining to the Orkney Islands.—n. an inhabitant or a native of the Orkneys. [L. Orcades.]

Orchard, or′chard, n. a garden of fruit-trees, esp. of apple-trees, also the enclosure containing such.—ns. Or′chard-house, a glass house for cultivating fruits without artificial heat; Or′charding; Or′chardist. [A.S. orceard—older form ort-geard.]

Orchella-weed=Archil (q. v.).

Orcheocele, or-ke-o-sēl′, n. a tumour or inflammation of the testicle.—ns. Orchial′gia, pain, esp. neuralgia, in a testicle; Orchidec′tomy, Orchot′omy, the excision of a testicle; Orchiodyn′ia, pain in a testicle; Orchī′tis, inflammation of a testicle.—adj. Orchit′ic. [Gr. orchis, a testicle, kēlē, a tumour.]

Orchestra, or′kes-tra, n. in the Greek theatre, the place where the chorus danced: now the part of a theatre or concert-room in which the musicians are placed: the performers in an orchestra.—ns. Orchē′sis, the art of dancing or rhythmical movement of the body; Orchesog′raphy, the theory of dancing.—adjs. Or′chestral, Orches′tric, of or pertaining to an orchestra: performed in an orchestra.—v.t. Or′chestrāte, to arrange for an orchestra.—ns. Orchestrā′tion, the arrangement of music for an orchestra: instrumentation; Orches′trion, a musical instrument of the barrel-organ kind, designed to imitate an orchestra. [L.,—Gr. orchēstraorchesthai, to dance.]

Orchid, or′kid, n. a plant with a rich, showy, often fragrant flower, frequently found growing, in warm countries, on rocks and stems of trees.—adjs. Orchidā′ceous, Orchid′ēous, pertaining to the orchids.—ns. Orchidol′ogy, the knowledge of orchids; Or′chis, a genus containing ten of the British species of orchids. [Gr. orchis, a testicle.]

Orchil, or′kil, n. the colouring matter derived from archil (q.v.).