The word is unique to Anglo-Norman and appears only in this text. Although Orengo translates it as the adverbial use of penable (‘par punition’ Dial Greg SATF i p. 483), its sense seems to be closer to that of the Continental French adjective penable (‘pénible, difficile à supporter’).
adv.
1in a manner which is painful, unbearable:
(
1212; MS: 1212-13
)
Li esperit [...] El cors vivant tenuz est vifs [...]. Di donc, por qei ne poet il mie Estre tenu penablement La ou deit vivre mortaument?
16815
penablement (1212)