Brick short of a load and Slow on the uptake

Slow on the uptake and brick short of a load are semantically related. In some cases you can use "Slow on the uptake" instead an adjective phrase "Brick short of a load".

Brick short of a load and slow on the uptake are semantically related. You can use "Brick short of a load" instead an adjective phrase "Slow on the uptake".