Cite the scanned version of the original dicionary like this:
Toller, T. Northcote, and Joseph Bosworth. "fæt." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth : Supplement. Oxford: Clarendon Press, 1921. 203.
, es; pl. nom. acc. fatu, fata; gen. fata; dat. fatum; n. A vessel, cup, VAT; vas, călix :-- Swá swá fæt crocwirhtan oððe tygelwirhtan ðú tobrytst híg tamquam vas fĭgŭli confringes eos, Ps. Lamb. 2, 9. Fætes botm the bottom of a vessel; vāsis fundum, Cot. 92. Mid ðam fæte with the vessel, Homl. Th. ii. 158, 19. He oferwríhþ nán man mid fæte his onælede leóhtfæt nēmo autem lucernam accendens, opĕrit eam vāse, Lk. Bos. 8, 16. In seolfren fæt in a silver vessel, Elen. Kmbl. 2050; El. 1026.
, fætt, es; n? A thin plate of metal, gold-leaf, ornament; lāmĭna, bractea :-- Sceal se hearda helm, hyrsted golde, fætum, befeallen the hard helmet, adorned with gold, with ornaments, shall be fallen off, Beo. Th. 4504, note; B. 2256. To ðæs ðe he goldsele gumena wisse, fættum fáhne until he perceived the golden hall of men, variegated with ornaments, 1436; B. 716.