, es; n. [werc = wærc pain] A pain in the buttocks; nătium dŏlor :-- Ðes drænc is gód wið endwerce this drink is good for pain in the buttocks, Lchdm. iii. 50, 11.
Cite the scanned version of the original dicionary like this:
Bosworth, Joseph. "end-werc." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth. Ed. Thomas Northcote Toller. Oxford: Clarendon Press, 1898. 251.