kangarooyoudaoicibaDictYouDict
kangaroo: [18] The first English speakers to refer in writing to the kangaroo were Captain Cook and the botanist Joseph Banks, who both mentioned it in 1770 in the journals they kept of their visit to Australia (Banks, for instance, referred to killing ‘kangaru’). This was their interpretation of ganjurru, the name for a large black or grey type of kangaroo in the Guugu Yimidhirr language of New South Wales.

English quickly generalized the term to any sort of kangaroo, although it caused some confusion among speakers of other Australian Aboriginal languages, who were not familiar with it: speakers of the Baagandji language, for instance, used it to refer to the horse (which had just been introduced into Australia). There is no truth whatsoever in the story that the Aboriginal word was a reply to the English question ‘What’s that?’, and meant ‘I don’t understand’.

The element -roo was used in the 19th century to produce jackeroo, which denoted ‘a new immigrant in Australia’, and is first recorded as an independent abbreviation of kangaroo in the first decade of the 20th century. The term kangaroo court ‘unofficial court’, which dates from the 1850s, is an allusion to the court’s irregular proceedings, which supposedly resemble the jumps of a kangaroo.
Arabic (adj.)youdaoicibaDictYouDict
early 14c., from Old French Arabique (13c.), from Latin Arabicus "Arabic" (see Arab). Old English used Arabisc "Arabish." Originally in reference to gum arabic; noun meaning "Arabic language" is from late 14c.

Arabic numerals (actually Indian) first attested 1727; they were introduced in Europe by Gerbert of Aurillac (later Pope Sylvester II) after a visit to Islamic Spain in 967-970. A prominent man of science, he taught in the diocesan school at Reims, but the numbers made little headway against conservative opposition in the Church until after the Crusades. The earliest depiction of them in English, in "The Crafte of Nombrynge" (c. 1350) correctly identifies them as "teen figurys of Inde."
geophagy (n.)youdaoicibaDictYouDict
"dirt-eating," 1820, from Greek *geophagia (according to OED the actual Greek is geotragia), from geo-, comb. form of ge "earth" (see Gaia) + phagein "to eat." See also pica (n.2).
A diseased appetite ... prevails in several parts of Alabama, where they eat clay. I heard various speculations on the origin of this singular propensity, called 'geophagy' in some medical books. [Lyell, "Second Visit to U.S.," 1850]
whitey (n.)youdaoicibaDictYouDict
"'white' person, person of European descent," 1828, also whity, from white (adj.) + -y (2) and -y (3). Earlier as an adjective, and Whitey-brown was a 19c. descriptive color name, used to describe, among other things, mulatto skin.
Negro troops doing provost duty in Norfolk; keeping the white people in order. On a visit to Norfolk one can see white Southerners, arrested for sundry misdemeanors, working on the public streets, under negro guards. ... It is quite a change to see, in Norfolk, negroes forcing white men to work, at the point of the bayonet; calling out to them: "No loaf'n dar!" "Move quicker, Sah!" "Hurry up dar, Old Whitey!" and similar orders. Tables turned! [diary of Lieut. S. Millett Thompson, 13th New Hampshire Volunteer regiment, U.S. Army, Jan. 25, 1864; diary published 1888 by Houghton, Mifflin & Co.]