I. roof 1 S2 W2 /ruːf $ ruːf, rʊf/ BrE AmE noun [countable]
[ Language: Old English ; Origin: hrof ]
1 . the structure that covers or forms the top of a building, vehicle, tent etc:
They finally found the cat up on the roof.
roof of
We can probably strap the cases to the roof of her car.
slate/tiled/thatched etc roof
a flat roof
a pitched roof (=sloping roof)
red-roofed/metal-roofed etc
a wooden-roofed theatre
2 . the top of a passage under the ground:
Suddenly, the whole tunnel roof caved in.
3 . a roof over your head somewhere to live:
I may not have a job, but at least I’ve got a roof over my head.
4 . go through the roof informal
a) ( also hit the roof ) to suddenly become very angry:
Put that back before Dad sees you and hits the roof!
b) if a price, cost etc goes through the roof, it increases to a very high level
5 . the roof of sb’s mouth the hard upper part of the inside of your mouth
6 . under the same roof/under one roof in the same building or home:
If we’re going to live under the same roof, we need to get along.
Here you can buy food, clothes, and electrical goods all under one roof.
7 . under sb’s roof spoken in your home:
As long as you live under my roof, you’ll do as I say.
8 . the roof falls/caves in informal especially American English if the roof falls in or caves in, something bad suddenly happens to you when you do not expect it
⇨ raise the roof at ↑ raise 1 (23), ⇨ ↑ sunroof
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COLLOCATIONS
■ ADJECTIVES/NOUN + roof
▪ a flat roof
She used to sunbathe on the flat roof.
▪ a sloping roof
The path led to a log cabin with a chalet-style sloping roof.
▪ a pitched roof (=with parts that slope down)
a row of garages with tiled pitched roofs.
▪ a tiled roof (=covered with pieces of baked clay)
▪ a slate roof (=covered with thin pieces of a grey rock)
▪ a thatched roof (=made of dried straw)
She lived in a pretty country cottage with a thatched roof.
▪ a leaky/leaking roof (=one that lets rain in)
We needed to fix the leaky roof.
II. roof 2 BrE AmE verb [transitive usually passive]
to put a roof on a building
be roofed with something
a cottage roofed with the local slate
roof something ↔ in/over phrasal verb British English
to cover an open space by putting a roof over it:
We’re going to roof in the yard to make a garage.