a long vertical solid structure, made of stone, brick or concrete, that surrounds, divides or protects an area of land
The fields were divided by stone walls.
He sat on the wall and watched the others playing.
any of the vertical sides of a building or room
I'm going to paint the walls white and the ceiling pink.
Hang the picture on the wall opposite the window.
She leaned against the wall.
something that forms a barrier or stops you from making progress
The boat struck a solid wall of water.
The investigators were confronted by a wall of silence .
the outer layer of sth hollow such as an organ of the body or a cell of an animal or a plant
the abdominal wall
the wall of an artery
of a company or an organization
to fail because of lack of money
unusual and amusing; slightly crazy
Some of his ideas are really off the wall.
crazy or angry
That noise is driving me up the wall.
I mustn't be late or Dad will go up the wall.
used to warn people to be careful what they say because other people may be listening
to be in a difficult situation in which you are forced to do sth but are unable to make the choices that you would like
to be so full of energy or so excited that you cannot keep still
a person who watches others without being noticed
I'd love to be a fly on the wall when he tells her the news.
fly-on-the-wall documentaries (= in which people are filmed going about their normal lives as if the camera were not there)
used when you are talking about keeping sth secret
Don't let this go further than these four walls (= Don't tell anyone else who is not in the room now) .
to keep trying to do sth that will never be successful
Trying to reason with them was like banging my head against a brick wall.
used when you are describing a situation in which there are signs that sth is going to have problems or that it is going to be a failure
It is amazing that not one of them saw the writing on the wall.
From the Bible story in which strange writing appeared on a wall during a feast given by King Belshazzar, predicting Belshazzar's death and the fall of his city.
to surround an area, a town, etc. with a wall or walls
a walled city
to surround sth/sb with a wall or barrier
to separate one place or area from another with a wall
to keep sb as a prisoner behind walls
to fill an opening with a wall, bricks, etc. so that you can no longer use it