late 14c., "the direction east; the part of the horizon where the sun first appears," also (now with capital O-) "the eastern regions of the world, eastern countries" (originally vaguely meaning the region east and south of Europe, what is now called the Middle East but also sometimes Egypt and India), from Old French orient "east" (11c.), from Latin orientem (nominative oriens) "the rising sun, the east, part of the sky where the sun rises," originally "rising" (adj.), present participle of oriri "to rise" (see origin).
Meaning "a pearl of the first water" is by 1831, short for pearl of the Orient (late 14c.) originally meaning one from the Indian seas. Hence also the meaning "a delicate iridescence, the peculiar luster of a fine pearl" (1755). The Orient Express was a train that ran from Paris to Istanbul via Vienna 1883-1961, from the start it was associated with espionage and intrigue.
by 1741, "to arrange (something) so as to face east," from French s'orienter "to take one's bearings," literally "to face the east" (also the source of German orientierung), from Old French orient "east," from Latin orientum (see orient (n.)). Extended meaning "place or arrange in any definite position with reference to the points of the compass" is by 1842; the figurative sense, with reference to new situations or ideas, is by 1850. Related: Oriented; orienting.
in reference to the competitive sport of finding one's way in the wild with the aid of a map and a compass, 1948, from orient (v.).
also re-orient, 1897, transitive, "give a new direction to;" 1937, intransitive, "adjust (to), come to terms with, adopt a new direction;" from re- "back, again" + orient (v.) or perhaps a back-formation from reorientation. Related: Reoriented; reorienting. Alternative reorientate is recorded from 1913. Tennyson uses reorient as an adjective, "arising again or anew."
late 14c., "of the orient; from the east," from Old French oriental "eastern, from the east" (12c.) and directly from Latin orientalis "of or belonging to the east," from orientem (see orient (n.)). Originally in reference to the sky, geographical sense, often with a capital O-, is attested from late 15c.; oriental carpet is recorded by 1828. Of gems or stones, "of superior quality," late 14c.
1839, "arrangement (of a building, etc.) to face east or any other specified direction," noun of action from orient (v.). Meaning "process of determining the points of the compass is by 1868, hence the extended sense of "action of determining one's mental bearings," with reference to new ideas, etc. (1870). Meaning "introduction to a situation" is from 1942. Sense of "the position or arrangement (of something) relative to the points of the compass" is from 1875. Related: Orientational.
"confuse as to direction," 1650s, from French désorienter "to cause to lose one's bearings," literally "to turn from the east," from dés- (see dis-) + orienter (see orient (v.)). Related: Disoriented; disorienting.
At the end of this labyrinth, when he had little guess where he had been conducted, and was, according to the French phrase, totally desorienté, (etc.). [Scott, "Redgauntlet," 1824]
The Latin sense shift in auster, if it is indeed the same word other Indo-European languages use for "east," for which Latin uses oriens (see Orient (n.)), perhaps is based on a false assumption about the orientation of the Italian peninsula, "with shift through 'southeast' explained by the diagonal position of the axis of Italy" [Buck]; see Walde, Alois, "Lateinisches etymologisches Wörterbuch," 3rd. ed., vol. I, p.87; Ernout, Alfred, and Meillet, Alfred, "Dictionnaire étymologique de la langue latine," 2nd. ed., p.94. Or perhaps the connection is more ancient, and from PIE root *aus- "to shine," source of aurora, which also produces words for "burning," with reference to the "hot" south wind that blows into Italy. Thus auster "(hot) south wind," metaphorically extended to "south."
"native or inhabitant of the east," 1701, from oriental (adj.). Probably a new use; Middle English had Oriental "a native of the Orient" (late 15c.), also "a resident of the eastern parts of England" (mid-15c.).