A potential, unsuspected, hidden problem, hazard, or danger that is easily encountered but not immediately obvious.
A type of trap consisting of a concealed pit in the ground, which the victim is supposed to fall into and not be able to get out from.
An antipattern.
Subsidence below ground in a mine, which can cause the ground level above to drop.
Wet sand that appears firm but in which things readily sink, often found near rivers or coasts.
Anything that pulls one down or buries one metaphorically