ἀραίωσις

English (LSJ)

εως, ἡ,

   A becoming or making porous, rarefaction, opp. πύκνωσις, dub. in Epicur.Nat.14Fr.11 (cf. Fr.6), cf. Plu.Strom.3, D.L.9.8 (Heraclit.), Corn.ND17, etc.    2 Medic., porosity, of the lungs, Hp. Oss.13, etc.    3 mordanting, PHolm. 8.3.

German (Pape)

[Seite 343] ἡ, das Dünnmachen, Auflockern, Arist. mund. 4 ὀμίχλη γίνεται ἐξ ἀραιώσεως νέφους; oft bei Hippocr. u. Sp., Ggstz πύκνωσις.