Answer:
Swamp.
Explanation:
A swamp is a natural environment, also called wetland, which is heavily forested by aquatic vegetation that can endure periodic inundations. Regardless of this definition, in colloquial terms, a swamp has come to acquire negative connotations that denote certain amounts of stagnation and even filth. One good example of this colloquialism is Trump´s famous phrase: drain the swam (implying: clean politics of corruption and economic interests).
