"no thing, not any thing, not something," Middle English, from Old English naþing, naðinc, from nan "not one" (see none) + þing "thing" (see thing). Meaning "insignificant thing, thing of no consequence" is from c. 1600. As an adverb, "not at all, in no degree," late Old English. As an adjective by 1961. For nothing "not at all" is from c. 1300. Nothing to it, indicating something easy to do, is by 1925. Nothing to write home about, indicating an unremarkable circumstance or thing, is from 1917 among the World War I soldiers.
word-forming element denoting action, quality, or state, attached to an adjective or past participle to form an abstract noun, from Old English -nes(s), from Proto-Germanic *in-assu- (cognates: Old Saxon -nissi, Middle Dutch -nisse, Dutch -nis, Old High German -nissa, German -nis, Gothic -inassus), from *-in-, originally belonging to the noun stem, + *-assu-, abstract noun suffix, probably from the same root as Latin -tudo (see -tude).