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.
transitive verb. 1 : to dissolve out by the action of a percolating liquid leach out alkali from ashes. 2 : to subject to the action of percolating (see percolate 1a) liquid (such as water) in order to separate the soluble components.