Nother

wiktionary

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From Old English nōhwæþer. Compare neither, nauther.

Variant of an other, another, influenced by re-analysis as a nother. Compare Middle English a noþer.

etymonline

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nother (pron.)

word formed from misdivision of another as a nother (see N for other examples), c. 1300. From 14c.-16c. no nother is sometimes encountered as a misdivision of none other or perhaps as an emphatic negative; Old English had noðer as a contraction of ne oðer "no other." Hence Middle English nother-gates (adv.) "not otherwise" (c. 1300).