Cite the scanned version of the original dicionary like this:
Bosworth, Joseph. "deáþ-þénunga." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth. Ed. Thomas Northcote Toller. Oxford: Clarendon Press, 1898. 198.
.Substitute:deáþ-þegnung, e; f. Ministration to the dead; pl. exequies :-- Deáþþénunga exequias, Wrt. Voc. ii. 30, 24. Hú mæg ic ðé ána gedéfelíce deáðþénunga gegearwian nymðe míne bróþor hider sín gesamnode? . . . Ðá þreó fǽmnan þám Maria hire deáþþénunga bebeád, Nap. 16.