This is a tautological construction, with the adverb nuitantre extended with the adverbial suffix; cf. FEW 7,162b. Both attestations may be dubious in their transcription.
(
1402
)
noetrandement par escheles [...] la cooperture des ditz tenementz debruserent
iii 488
(
1416
)
d'illeoqes sodenement amesnez ové lour chivalx, et hernois, tanqe a un mountyn appellé Dynmorehille en mesme le counté, et illeoqes de lour chivalx et harnois despoillez, et d'illeoqes noetaundrent (l. noetaundr[em]ent), la noet ensuyant, tanqe a un chapelle disconuz
iv 99.15
[nuitantrement] (1402)