The Collaborative International Dictionary
Winterkill \Win"ter*kill`\, v. i. To die as the result of exposure to the cold of winter; as, the tree winterkills easily.
Winterkill \Win"ter*kill`\, v. t. [imp. & p. p. Winterkilled; p. pr. & vb. n. Winterkilling.] To kill by the cold, or exposure to the inclemency of winter; as, the wheat was winterkilled. [U. S.]
Wiktionary
n. The mortality resulting from lethal wintry conditions among a human, animal(,) and/or vegetal population. vb. 1 (context transitive English) To kill by the conditions of winter, especially the effect of the cold, freezing. 2 (context intransitive English) To die from the above effects of winter conditions.
Usage examples of "winterkill".
The stations down there report that the winterkill is just devastating.
Looking across the bumpy white waste, feeling the wind cut through one of the thicker insulated walkers, it seemed to Sax that a very severe winterkill was inevitable.
Once she even thought she might have seen something move across a patch of winterkilled grass that looked pale against the darker rocks and forest.