next adj.

"next to," c. 1400, from a- (1) + next.

also nextdoor, "in or at the next house," 1570s, from noun phrase next door "nearest or adjoining house" (late 15c.), from next + door. As an adjective from 1660s. Noun meaning "the people living next door" is from 1855. Middle English dwellen at dores (late 14c.) meant "live next door."

"near, nearby, close together, adjacent," Middle English neigh, from Old English neah (West Saxon, Kentish), neh (Anglian), from Proto-Germanic *naehwa- (source also of Old Saxon nah, Old Frisian nei, Middle Dutch, Dutch na, Old High German nah, German nah, Gothic nehwa), of uncertain origin, with no cognates outside Germanic. The Old English progression was neah - near - niehsta, for "nigh - nigher - nighest." But the comparative near and the superlative nehst (see next) gradually evolved into separate words that were no longer felt as related to nigh. New comparative and superlative forms nigher, nighest developed 14c. as phonetic changes obscured the original relationships. As an adjective and preposition in Middle English.