Cite the scanned version of the original dicionary like this:
Toller, T. Northcote, and Joseph Bosworth. "eorþ-gráp." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth : Supplement. Oxford: Clarendon Press, 1921. 192.
, e; f. Earth's grasp, the hold of the grave; terræ comprĕhensio :-- Eorþgráp hataþ waldend wyrhtan earth's grasp [i. e. the grave holdeth its mighty workmen, Exon. 124 a; Th. 476, 12; Ruin. 6.