Also called rime ice. an opaque coating of tiny, white, granular ice particles, caused by the rapid freezing of supercooled water droplets on impact with an object. Compare frost(def. 2), glaze(def. 17).
"hoarfrost," O.E. hrim, from P.Gmc. *khrima- (cf. O.N. hrim, Du. rijm, Ger. Reif). O.Fr. rime is of Gmc. origin. Rare in M.E., surviving mainly in Scottish and northern Eng., revived in literary use late 18c.