Cite the scanned version of the original dicionary like this:
Toller, T. Northcote, and Joseph Bosworth. "un-áwendendlic." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth : Supplement. Oxford: Clarendon Press, 1921. 732.
;adj. Unchangeable, unalterable, invariable :-- Heora nán nǽfre of ðam háde ðe hé is ne áwent, forðan ðe God is unáwendendlíc, Homl. Th. ii. 606, 27: Bt. 35, 2; Fox 158, 4. God is ealra ðinga reccend and hé ána unáwendendlíc wunaþ and eallra ðara áwendendlícra welt rerum orbem mobilem rotat, dum se immobilem ipsa conservat, 35, 5; Fox 166, 9. Sió godcunde foreteohhung is ánfeald and unáwendendlíc (simplex immobilisque), 39, 6; Fox 220, 16. God gesette unáwendendlícne sido, 21; Fox 74, 1. Eorþan ðú sealdest unáwendendlíce terram dedisti immobilem, Hymn.