DCHP-1 Online
crust 
n. a layer of frozen snow overlying softer snow, formed by the melting and refreezing of the surface, aided by wind compaction.
See also: snow-crust
- 1776 (1792) It was exceedingly bad walking to-day, and also very bad for the eyes; the snow having a crust on it which reflected as much as cut glass, and every tree had assumed a most brilliant lustre, from the effect of the silver thaw.
- 1826 It was impossible for any animal to travel, whose feet were not armed with points to penetrate the crust, or heavy enough to break it, in which case, its legs were wounded and in constant danger of being broken.
- 1955 Over the crisp crust of the day before my snowshoes had made some noise, and I had paid the matter no attention.
- 1776 (1792) It was exceedingly bad walking to-day, and also very bad for the eyes; the snow having a crust on it which reflected as much as cut glass, and every tree had assumed a most brilliant lustre, from the effect of the silver thaw.