nigh (adv.) Look up nigh at Dictionary.com
"near," Old English neah (West Saxon), neh (Anglian), common Germanic (cognates: Old Saxon nah, Old Frisian nei, Middle Dutch, Dutch na, Old High German nah, German nah, Gothic nehwa), with no cognates outside Germanic. The Old English progression was neah - near - niehsta, for "nigh - near - next." But the comparative near and the superlative nehst (see next) gradually evolved into separate words not felt as related to nigh. New comparative and superlative forms nigher, nighest developed 14c. as phonetic changes obscured the original relationships. As an adjective from Middle English.