big, huge, large, massive
small
solid
cement, concrete, ice, stone, wood, wooden
building
rectangular
starting (for a runner)
I was aiming to be first out of the starting blocks.

stumbling (figurative)
The issue has been a major stumbling block in trade negotiations.

breeze (BrE), cinder (AmE)

on the chopping block
I'm not putting my head on the chopping block (= putting myself at risk) for you.

high-rise, tower
tenement (BrE)
administration, apartment, cell, office
The prisoners had been transferred to a different cell block.

in a/the block
She lives in a modern apartment block.

block of
a block of flats

city
The hotel occupies an entire block.

around the block, round the block (esp. BrE)
People were queueing round the block to get in. (BrE)
Fans lined up around the block to get tickets for the show. (AmE)

block from (AmE)
We're about four blocks from my house.

block down (AmE)
They walked a few blocks down the street.

mental, writer's
The author denies that she is experiencing writer's block.

experience, have, suffer from
I suddenly had a mental block and couldn't remember his name.

completely
almost
partially, partly
off, up
The old route is completely blocked off.
Don't block up the corridor with all these boxes.

try to
move to
One of the men moved to block their path.

with
The exit was blocked with beer crates.

successfully
effectively
The new rules would effectively block protesters' attempts to assert their rights.

attempt to, seek to, try to
move to
The group has moved to block the government's proposals.

completely
Black clouds had completely blocked out the sun.

almost