This might be just a supplemental entry adding to an entry in the Main Volume.
ceder-treów
.Add :-- Neorxnawanges cedertreów, Gr. D. 191, 7. Cedertrýwes twyg, Angl. viii. 332, 37. Cedortreówu ... þá myclan cedertreówu cedros ... cedros Libani, Ps. Th. 28, 5.
Cite the scanned version of the original dicionary like this:
Toller, T. Northcote, and Joseph Bosworth. "ceder-treów." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth : Supplement. Oxford: Clarendon Press, 1921. 12.