What does "hoarfrost" mean?

Alternative form of hoar frost.

What is a synonym for "hoarfrost"?

Common synonyms include: frost, rime, crystal lace, danish frost, frost film, frost layer.

noun

noun ·Rare ·Advanced level

Noun

1
Alternative form of hoar frost. alt-of, alternative, uncountable, usually
"[…] It is moſt remarkable on the ſurface of ſnovv, vvhen covered vvith hoarfroſt, and on other bodies vvhere hoarfroſt moſt abounds. In ſuch caſes, I have often found the ſurface to be ſeven degrees colder than the air at the diſtance of tvvo feet; […]"
2
ice crystals forming a white deposit (especially on objects outside) wordnet

"The hoarfrost has not begun to thaw yet."