This is the 404th most frequent Dutch word.
poel
A small pond or pool.
Here, 'poel' is used to refer to a natural body of water, typically small, like a pond or pool.
De kikker sprong in de poel naast het bos.
The frog jumped into the pool next to the forest.
Here, 'poel' is used metaphorically to describe a concentration or gathering of an abstract concept, in this case, corruption.
De organisatie was een poel van corruptie.
The organization was a pool of corruption.
In this instance, 'poel' describes a collection or accumulation of liquid, not necessarily water, that forms a pool-like area.