A block of flats or offices is a large building containing them.

A block in a town is an area of land with streets on all its sides.

A block of a substance is a large rectangular piece of it.

To block a road, channel, or pipe means to put an object across it or in it so that nothing can pass through it or along it.

If something blocks your view, it prevents you from seeing something because it is between you and that thing.

If you block something that is being arranged, you prevent it from being done.

In some sports, if a player blocks a shot or kick, they stop the ball reaching its target. If one player blocks another, the first stops the second from reaching or moving with the ball.

A block of something such as tickets or shares is a large quantity of them, especially when they are all sold at the same time and are in a particular sequence or order.

If you have a mental block or a block, you are temporarily unable to do something that you can normally do which involves using, thinking about, or remembering something.

If someone lays their head on the block, or puts their head on the block, they are risking their reputation or position by taking a particular course of action.