As a proper noun frost
As a noun sleet is
(chiefly|uk|ireland) a mixture of rain and snow.
As a verb sleet is
(impersonal|of the weather) to be in a state in which sleet is falling.
A cover of minute ice crystals on objects that are exposed to the air. Frost is formed by the same process as dew, except that the temperature of the frosted object is below freezing.
* 1748 . David Hume. Enquiries concerning the human understanding and concerning the principles of moral. London: Oxford University Press, 1973. § 47.
The cold weather that causes these ice crystals to form.
(figurative) Coldness or insensibility; severity or rigidity of character.
* Sir Walter Scott
- It is more probable, in almost every country of Europe, that there will be frost sometime in January, than that the weather will continue open throughout that whole month;
(obsolete) The act of freezing; the congelation of water or other liquid.
- It was one of those moments of intense feeling when the frost of the Scottish people melts like a snow-wreath.
* black frost
* degree of frost
* hoar frost, hoarfrost
* Jack Frost
* uremic frost
To get covered with frost .
To coat something (e.g. a cake) with icing to resemble frost.
To anger or annoy.
- I think the boss's decision frosted him, a bit.
(chiefly, UK, Ireland) A mixture of rain and snow.
Rain which freezes before reaching the ground.
(firearms) Part of a mortar extending from the chamber to the trunnions.
* ice pellets
* freezing rain
(impersonal, of the weather) To be in a state in which sleet is falling.
- I won't bother going out until it's stopped sleeting .
AMS Glossary of Meteorology