frost up
Verb
Meaning
frost up (third-person singular simple present frosts up, present participle frosting up, simple past and past participle frosted up)
(intransitive) to become frosty
The windows often frost up in winter.
Verb
frost up (third-person singular simple present frosts up, present participle frosting up, simple past and past participle frosted up)
(intransitive) to become frosty
The windows often frost up in winter.