Cite the scanned version of the original dicionary like this:
Bosworth, Joseph. "sceald-húlas." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth. Ed. Thomas Northcote Toller. Oxford: Clarendon Press, 1898. 822.
.Substitute: some kind of sedge :-- Scaldhúlas paupilius (cf. eolxsegc papilluum, i. 286, 36), Wrt. Voc. ii. 116, 21. [v. N. E. D. shalder rush or sedge.]