"ogre, devouring monster," 1590s, perhaps a reborrowing of the same word that became Old English orcþyrs, orcneas (plural), which is perhaps from a Romanic source akin to ogre, and ultimately from Latin Orcus "Hell," a word of unknown origin. Also see Orca. Revived by J.R.R. Tolkien (1892-1973), who might have got it from Beowulf, as the name of a brutal race in Middle Earth.
But Orcs and Trolls spoke as they would, without love of words or things; and their language was actually more degraded and filthy than I have shown it. ["Return of the King," 1955]
"killer whale," introduced as a generic term for the species by 1841, from earlier use in scientific names, from Latin orca "cetacean, a kind of whale." Earlier in English, orc, ork "large marine mammal, deadly sea-creature" (by mid-17c.), from French orque, had been used vaguely of sea monsters (see orc). Strong, ferocious, and predatory, they are the only cetaceans which habitually prey upon warm-blooded animals.
c. 1600, "area in an ancient theater for the chorus," from Latin orchestra, from Greek orkhēstra, semicircular space where the chorus of dancers performed, with suffix -tra denoting place + orkheisthai "to dance," perhaps an intensive of erkhesthai "to go, come," but not all experts accept that (see Beekes).
In ancient Rome, orchestra referred to the place in the theater reserved for senators and other dignitaries. Meaning "group of musicians performing at a concert, opera, etc." is recorded by 1720, so called because they occupy the position of the orchestra relative to the stage ; that of "part of theater in front of the stage" is from 1768 in English.
Some related words still retain the "dancing" sense: Orchestic "of or pertaining to dancing" (1712), also orchestric (1740).
late Old English orceard "fruit garden; piece of ground, usually enclosed, devoted to the culture of fruit-trees," also for meeting, recreation, etc., earlier ortgeard, perhaps reduced from wortgeard, from wort (Old English wyrt "vegetable, plant root") + geard "garden, yard" (also "vegetable garden" until 15c.); see yard (n.1). The first element would have been influenced in Middle English by Latin hortus (in Late Latin ortus) "garden," which also is from the PIE root (*gher- (1) "to grasp, enclose") that yielded yard (n.1). Orchard-house "glass house for the cultivation of fruits too delicate to be grown in open air" is by 1850.
1845, introduced by John Lindley in the third edition of "School Botany," from Modern Latin Orchideæ (Linnaeus), the plant's family name, from Latin orchis, a kind of orchid, from Greek orkhis (genitive orkheos) "orchid," literally "testicle," from PIE *h(o)rghi-, the standard Indo-European word for "testicle" (source also of Avestan erezi, Armenian orjik'"testicles," Old Irish uirge, Hittite arki- "testicle," Lithuanian eržilas "stallion").
The plant so called because of the shape of its root; Greek orkhis also was the name of a kind of olive, also so called for its shape. Earlier in English in Latin form, orchis (1560s), and in Middle English it was ballockwort (c. 1300; see ballocks). The modern word is marred by an extraneous -d- in an attempt to extract the Latin stem. Related: Orchidaceous.
1840, "the act, process, or art of arranging music for an orchestra," from French orchestration (see orchestrate). U.S. slang sense of "an overcoat" is by 1940.
"to compose or arrange (music) for an orchestra," 1855, back-formation from orchestration. The figurative sense ("to coordinate, combine harmoniously") is attested from 1883. Related: Orchestrated; orchestrating.