ETYMOLOGY
from Old English beswincan, from be- + swincan (to toil, to labour)
definition 2: probably for beswinge (as per OED)
EXAMPLE (for vb. 2.)
“… “Here now,” quod hunger “and holde it for a wisdome:
Bolde beggeres and bigge þat mowe her bred biswynke,
With houndes bred and hors bred holde vp her hertis,
Abate hem with benes for bollyng of her wombe;
And ȝif þe gomes grucche bidde hem go swynke,
And he shal soupe swettere whan he it hath deseruid ….”
From: The Vision of William concerning Piers the Plowman
By William Langland, 1377
Lexicophilia 