1 B2 idiomatic informal
Of a kettle, pipe, or boiler: to develop a hard, chalky internal coating caused by mineral deposits in hard water.
"Our kettle furs up so quickly — we have to descale it every few weeks."
inseparable
fur up
B2 informal inseparable intransitive
To become coated with a furry or scaly deposit, especially the inside of a kettle, pipe, or boiler due to mineral build-up from hard water.
In plain English
When the inside of a kettle or pipe gets a white crusty coating from the minerals in water.
What does "fur up" mean?
2 meanings, ordered from most common to least. Color-coded by CEFR level.
2 C1 idiomatic informal
Of arteries or blood vessels: to become narrowed or blocked by a build-up of fatty or mineral deposits.
"Years of poor diet had caused his arteries to fur up, putting him at serious risk of a heart attack."
inseparable
Literal vs figurative
Words literally mean
To develop a fur-like coating on the inside surface.
Actually means
When the inside of a kettle or pipe gets a white crusty coating from the minerals in water.
Usage tip
Predominantly British English. 'Furring' refers to the white limescale deposit that forms inside kettles and pipes in hard-water areas. The term is also occasionally used metaphorically to describe arteries becoming blocked with fatty deposits. More commonly used in British English than American.
Words that pair with "fur up"
Natural word combinations native speakers use most often.
kettle pipes boiler arteries quickly badly
How to conjugate "fur up"
The five tense forms you'll use most often.
Base
fur up
I/you/we/they
3rd person
furs up
he/she/it
Past simple
fured up
yesterday
Past participle
fured up
have + pp
-ing form
furing up
continuous
Hear "fur up" in the wild
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