Needs
Old English nēdes (see need, -s3).
wiktionary
From Middle English nedes(“of necessity, necessarily; inevitably, unavoidably”)[and other forms], [1] from Old English nēdes, nīedes(“of necessity; not willingly”), originally the genitive form of nīed(“necessity, need; distress”), from nīed + -es( suffix forming adverbs from nouns). Nīed is ultimately derived from Proto-Indo-European *naut-(“misfortune, torment”), from *nāw-(“corpse; the dead”).
The English word is equivalent to need + -'s(possessive marker) and hence to need + -s(suffix forming adverbs). [2]
From need + -s.
From need + -s.
etymonline
needs (adv.)
"of necessity, necessarily," late 14c. and surviving in archaic constructions involving must, from Middle English nede (see need), used as an adverb reinforcing must (v.), hence the genitive ending.
