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.
verb. 1  To withdraw from or vacate a place or area, especially as a protective measure: The mayor urged the residents to evacuate before the hurricane struck. 2  To excrete waste matter from the body.