An Etymological Dictionary of Astronomy and Astrophysics

A very thin fog consisting of an aggregate of microscopic water droplets or wet hygroscopic particles (of diameter not less than 0.5 mm), in which the visibility at the earth’s surface is greater than 1 km.

Etymology (EN): O.E. mist “dimness, mist,” from P.Gmc. *mikhstaz
(cf. M.L.G. mist, Icelandic mistur), from PIE *migh-/*meigh-;
cf. Pers. miq “fog, mist;” Gk. omikhle, O.C.S. migla, Skt. megha- “cloud, mist.” → nebula.

Etymology (PE): Nezm “mist, fog,” variants nezu, nezvâ “mist,” nam “moisture, humidity;”
Av. napta- “moist,” nabās-câ- “cloud,” nabah- “sky;” cf. Skt. nábhas- “moisture, cloud, mist;” Gk. nephos “cloud, mass of clouds,” nephele “cloud;” L. nebula “mist,” nimbus “rainstorm, rain cloud;” O.H.G. nebul; Ger. Nebel “fog;” O.E. nifol “dark;” from PIE *nebh- “cloud, vapor, fog, moist, sky.”