cryohydrate
/krʌɪə(ʊ)ˈhʌɪdreɪt/Chemistry. Now rare
noun
A solid substance having a distinct composition and melting point formed by the combination of a salt or other crystalline compound with water (ice) at a temperature below freezing.
Origin
Late 19th century; earliest use found in Frederick Guthrie (1833–1886), chemist and physicist. From cryo- + hydrate.