Frost

Part of speech: noun, verb

Pronunciation: /fɹɒst/

Definitions

1. A thin layer of ice crystals that forms on surfaces when temperature drops below freezing, or the process by which this crystalline coating develops
2. A crystalline icy coating that accumulates on exposed surfaces during freezing temperatures, or the meteorological phenomenon creating such frozen deposits
3. The formation of delicate ice crystals on objects when atmospheric moisture freezes at or below zero degrees Celsius, or the resulting white crystalline layer itself

Etymology: The word "frost" is a good example of a sound change hiding in plain sight. Old English had the form "forst," and the familiar "frost" arose when the consonants swapped places, a process called metathesis, in the centuries before Middle English. The older form survives in German "Frost" and Dutch "vorst," which keep the original order of sounds. Its deeper roots point to freezing. Proto-Germanic "frustaz" belongs to a Proto-Indo-European root meaning "to freeze," and the same root gave English "freeze" through a separate line of descent. That makes "frost" and "freeze" close relatives, a connection that is easy to miss because the two words look and sound so different today. The family reaches beyond the Germanic languages. Latin "pruīna," meaning hoarfrost or rime, is a distant cousin, though it entered Latin along its own path and is not the direct source of the English word.

Synonyms: ice, freeze, glaze, chill, rime

Antonyms: heat, warmth, thaw, tropical, sunshine