Cite the scanned version of the original dicionary like this:
Bosworth, Joseph. "hæft-encel." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth. Ed. Thomas Northcote Toller. Oxford: Clarendon Press, 1898. 499.
.Substitute:hæftinoel, es; n. An enslaved captive, a captive bought and made a slave. Cf. hæft; II :-- Hæftincel empticius (cf. emptilius geboht þeówa, i. 50, 16), Wrt. Voc. ii. 30, 34.