ivory:  As is hardly surprising, ivory goes back ultimately to an African word which meant both ‘ivory’ and ‘elephant’. A likely candidate as this source is Egyptian āb, which may well lie behind Latin ebur ‘ivory’. This passed into English via Old French ivurie. The expression ivory tower ‘place where reality is evaded’ is a translation of French tour d’ivoire. This was originally used in 1837 by the French critic Sainte-Beuve with reference to the poet Alfred de Vigny, whom he accused of excessive aloofness from the practicalities of the world. The English version is first recorded in 1911.
mid-13c. (late 12c. as a surname), Anglo-French ivorie, from Old North French ivurie (12c.), from Latin eboreus "of ivory," from ebur (genitive eboris) "ivory," probably via Phoenician from an African source (compare Egyptian ab "elephant," Coptic ebu "ivory"). Replaced Old English elpendban, literally "elephant bone." Applied in slang to articles made from it, such as dice (1830) and piano keys (1854). As a color, especially in reference to human skin, it is attested from 1580s. Ivories as slang for "teeth" dates from 1782. Related: Ivoried.