Certain “poor whites” in the South use a sort of semi-edible clay. The word is employed as a term of reproach and scorn.

1

1841.  He was a little, dried up, withered atomy—a jaundiced “sand-lapper,” or “clay-eater,” from the Wassamasaw country, whose insignificant size and mean appearance did very inadequate justice to his resolute, fierce, and implacable character.—W. G. Simms, ‘The Kinsmen,’ i. 167 (Phila.).

2

a. 1860.  See Bartlett.

3

1901.  The terms “sand-hiller,” “clay-eater,” or “poor white trash,” conveyed a terrible reproach, for even the negroes looked down upon them.—W. Pittenger, ‘The Great Locomotive Chase,’ p. 74 (Phila.).

4