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.
Example Sentences for subsided. Again the same language of resignation; but the spirit has subsided since, and we hear no more of it. The cry that the church was in danger, had not yet subsided. With some difficulty Barney had got hold of Pat, whose barking had subsided into a rumbling growl.