Some people only have the problem when they run water in a sink or a bathtub. The source of the odor in almost all of these instances is a buildup of biofilm on the sides of the pipes that connect the sink or fixture to the actual P-shaped trap under the fixture.
Subsided is defined as  calmed down or sunk to a lower level. When the noise of a crowd dies down, this is an example of when the noisesubsided.
1. a disturbance on the surface of a liquid body, as the sea or a lake, in the form of a moving ridge or swell. 2. any surging or progressing movement or part resembling a wave of the sea. 3. a swell, surge, or rush: a wave of disgust.