geophagyn.

1821 H. M. Williams tr. A. von Humboldt Personal Narr. Trav. V. ii. 646 The attention of physiologists, since my return from the Oroonoko, having been powerfully fixed on these phenomena of geophagy [Fr. géophagie].

1850 C. Lyell 2nd Visit U.S. (ed. 2) II. 7 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.

1897 T. C. Allbutt et al. Syst. Med. II. 1043 Perverted appetite—pica or geophagy, as it is sometimes called—is a common occurrence in..intestinal helminthiasis.

1961 F. G. Cassidy Jamaica Talk vii. 132 A disease brought over from Africa..was geophagy, locally known as dirt-eating, earth-eating.

1991 New Scientist 30 Mar. 41/2 These methods include freeze-drying and leaching of the tubers to remove toxins, and geophagy, the eating of clay.

2005 P. W. Abrahams in O. Selinus Essent. Med. Geol. xvii. 450/1 Because all wild potatoes are poisonous to humans, the domestication of the modern potato..may have required geophagy at first.