Frŏst1, n.
(21), n. [A-S. forst, frost, from fréosan, frysan, to freeze; O. Sax., Icel., Sw., Dan., O. H. Ger., & N. H. Ger. frost, M. H. Ger. vrost, D. vorst, Goth. frius. See FREEZE.]
Sense 1. The act of freezing; — applied chiefly to the congelation of water; congelation of fluids.
Sense 2. That state or temperature of the air which occasions congelation, or the freezing of water; severe cold or freezing weather.
The third day comes a frost, a killing frost. Shak.
Nipped with the lagging rear of winter's frost. Milton.
Sense 3. Frozen dew; — called also hoar-frost or white-frost.
He scattereth the hoar-frost like ashes. Ps. cxlvii. 16.
Sense 4. Coldness or insensibility of temperament; harsh, stern, or repulsive manner; severity or rigidity of character. [Rare.]
It was one of those moments of intense feeling when the frost of the Scottish people melts like a snow-wreath. W. Scott.
Black frost, cold so intense as to freeze vegetation and cause it to turn black, without the formation of white or hoar frost.