1 B1 neutral
For a surface to become covered with a thin layer of frost or ice during cold weather.
"The car windscreen had frosted up overnight and I had to scrape it before driving."
inseparable
frost up
B1 neutral inseparable transitive/intransitive
For a surface to become covered with frost or a thin layer of ice.
In plain English
When frost forms on a window, windscreen, or other surface on a cold day.
What does "frost up" mean?
2 meanings, ordered from most common to least. Color-coded by CEFR level.
2 B2 neutral
To deliberately coat a glass surface with a frosted or opaque finish.
"They frosted up the bathroom window to give more privacy without blocking the light."
separable
Literal vs figurative
Words literally mean
To frost over the top — largely transparent.
Actually means
When frost forms on a window, windscreen, or other surface on a cold day.
Usage tip
Used commonly in British English to describe windows, windscreens, and outdoor surfaces. 'The windscreen has frosted up' is a typical use. Also used transitively: 'The cold frosted up the windows'.
Words that pair with "frost up"
Natural word combinations native speakers use most often.
windscreen window pipes roads glass surface
How to conjugate "frost up"
The five tense forms you'll use most often.
Base
frost up
I/you/we/they
3rd person
frosts up
he/she/it
Past simple
frosted up
yesterday
Past participle
frosted up
have + pp
-ing form
frosting up
continuous
Hear "frost up" in the wild
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