"a roundabout or circuitous way," 1738, from French détour, from Old French destor "side road, byway; evasion, excuse," from destorner "turn aside," from des- "aside" (see dis-) + tourner "to turn" (see turn (v.)). In 18c. usually figurative. Usually treated as a French word in English (with italics and the accent mark) until late 19c.
early 13c., of a wheel, "to rotate, roll over," from over- + turn (v.). Attested from c. 1300 in general transitive sense "to throw over violently;" figurative meaning "to ruin, destroy" is from late 14c. Of judicial decisions, "to reverse," it is attested from 1826. Related: Overturned; overturning. Old English had oferweorpan "to overturn, overthrow."
early 14c., returnen, "to come back, come or go back to a former position" (intransitive), from Old French retorner, retourner "turn back, turn round, return" (Modern French retourner), from re- "back" (see re-) + torner "to turn" (see turn (v.)). Also in part from Medieval Latin retornare, returnare.
The transitive sense of "report officially, give an official statement or account" (in answer to a writ or demand) is from early 15c.; "to send (someone or something) back" is by mid-15c.; that of "to turn back" is from c. 1500. Meaning "to give in repayment or recompense" is from 1590s; that of "give back, restore" is from c. 1600. Related: Returned; returning.
"the outline of a figure," 1660s, a term in painting and sculpture, from French contour "circumference, outline," from Italian and Medieval Latin contornare "to go around," from assimilated form of Latin com-, here perhaps an intensive prefix (see com-), + tornare "to turn (on a lathe);" see turn (v.).
Application to topography is from 1769. Earlier the word was used to mean "bedspread, quilt" (early 15c.) in reference to its falling over the sides of the mattress. Contour line in geography is from 1844. Contour-chair, one designed to fit the curves of the body, is from 1949.
As a verb, "mark with contour lines; form to the contours of," 1871. Related: Contoured.