Chapter Orphanage to Orthoptera of O by Webster's Dictionary (1913 Edition)

Orrach
(Or"rach) n. See Orach.

Orrery
(Or"re*ry) n.; pl. Orreries [So named in honor of the Earl of Orrery.] An apparatus which illustrates, by the revolution of balls moved by wheelwork, the relative size, periodic motions, positions, orbits, etc., of bodies in the solar system.

Orris
(Or"ris) n. [Prob. corrupted from It. ireos iris. See Iris.] (Bot.) A plant of the genus Iris (I. Florentina); a kind of flower-de- luce. Its rootstock has an odor resembling that of violets.

Orris pea (Med.), an issue pea made from orris root. — Orris root, the fragrant rootstock of the orris.

Orris
(Or"ris) n.

1. [Contr. from orfrays, or from arras.] A sort of gold or silver lace. Johnson.

2. A peculiar pattern in which gold lace or silver lace is worked; especially, one in which the edges are ornamented with conical figures placed at equal distances, with spots between them.

Orsedew
(Orse"dew Or"se*due) n. Leaf metal of bronze; Dutch metal. See under Dutch.

Orseille
(||Or`seille") n. [F.] See Archil.

Orsellic
(Or*sel"lic) a. [From F. orseille archil. See Archil.] (Chem.) Pertaining to, or designating, an acid found in certain lichens, and called also lecanoric acid. [Formerly written also orseillic.]

Orsellinic
(Or`sel*lin"ic) a. (Chem.) Pertaining to, or designating, an organic acid obtained by a partial decomposition of orsellic acid as a white crystalline substance, and related to protocatechuic acid.

Ort
(Ort) n.; pl. Orts [Akin to LG. ort, ortels, remnants of food, refuse, OFries. ort, OD. oorete, ooraete; prob. from the same prefix as in E. ordeal + a word akin to eat.] A morsel left at a meal; a fragment; refuse; — commonly used in the plural. Milton.

Let him have time a beggar's orts to crave.

Shak.

Ortalidian
(Or`ta*lid"i*an) n. (Zoöl.) Any one of numerous small two-winged flies of the family Ortalidæ. The larvæ of many of these flies live in fruit; those of others produce galls on various plants.

Orthid
(Or"thid) n. (Zoöl.) A brachiopod shell of the genus Orthis, and allied genera, of the family Orthidæ.

Orthis
(||Or"this) n. [NL., fr. Gr. 'orqo`s straight.] (Zoöl.) An extinct genus of Brachiopoda, abundant in the Paleozoic rocks.

Orthite
(Or"thite) n. (Min.) A variety of allanite occurring in slender prismatic crystals.

Ortho-
(Or"tho-) [Gr. straight; akin to Skr. rdhva upright, vrdh to grow, to cause to grow.]

1. A combining form signifying straight, right, upright, correct, regular; as, orthodromy, orthodiagonal, orthodox, orthographic.

2. (Chem.) A combining form (also used adjectively), designating: (a) (Inorganic Chem.) The one of several acids of the same element (as the phosphoric acids), which actually occurs with the greatest number of hydroxyl groups; as, orthophosphoric acid. Cf. Normal. (b) (Organic Chem.) Connection with, or affinity to, one variety of isomerism, characteristic of the benzene compounds; — contrasted with meta- or para-; as, the ortho position; hence, designating any substance showing such isomerism; as, an ortho compound.