monaþseoc

From mōnaþ (“moon, month”) +‎ sēoc (“sick”), derived from the idea that the moon could cause intermittent insanity (compare lūnāticus, with the same origin).

• IPA^(key): /ˈmoː.nɑθˌse͜oːk/

mōnaþsēoc f

1. insane, lunatic, moonstruck
2. epileptic
3. menstruating
   • Homilies of the Anglo-Saxon Church

     Ġelēaffulle lǣwede menn, þe on rihtum sinsċipe lybbað, āġifað þrītiġfealdne wǣstm gōdra weorca, ġif hī heora ǣwe æfter bōclīcum ġesetnyssum healdað, þæt is, þæt hī for bearnes ġestrēone, on alyfedum tīman, hǣmed begān, and bearneacniġende wīf and mōnaðsēoc forbūgan; and ðonne hēo leng tȳman ne mæġ,̇ ġeswican hī hǣmedes.

     Faithful lay people, who live in righteous marriage, yield thirtyfold fruit of good works, if their marriage follows the biblical decrees; that is, that they have intercourse for the procreation of children at permitted times, and abstain from intercourse with pregnant or menstruating women, and that at the time they can no longer procreate, they cease intercourse.

• mōnaþādl (“menstruation”, literally “monthly disease”)

• Joseph Bosworth; T. Northcote Toller (1898), “mónaþseóc”, in An Anglo-Saxon Dictionary, second edition, Oxford: Oxford University Press.