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.
The verb suffuse means to spread and fill a space, like the way the smell of wildflowers might suffuse a meadow. Suffuse is a synonym for steep. Like tea whose flavor grows stronger the more it steeps, when you suffuse something it spreads throughout until an area is full, or even overly full. Another synonym, infuse, looks a lot like suffuse. Both words come from the Latin word fundere, which means to pour.