n. [ NL., fr. Gr. kry`os icy cold, frost + fe`rein to bear. ] (Chem.) An instrument used to illustrate the freezing of water by its own evaporation. The ordinary form consists of two glass bulbs, connected by a tube of the same material, and containing only a quantity of water and its vapor, devoid of air. The water is in one of the bulbs, and freezes when the other is cooled below 32° Fahr. [ 1913 Webster ]