Definition of "congestion"

The hindrance or blockage of the passage of something, for example a fluid, mixture, traffic, people, etc. (due to an excess of this or due to a partial or complete obstruction), resulting in overfilling or overcrowding.

1. An accumulation or buildup, the act of gathering into a heap or mass.  examples

2. (medicine) Blocking up of the capillary and other blood vessels, etc., in any locality or organ (often producing other morbid symptoms); local hypermic, active or passive  examples

An excess or accumulation of something

1. An excess of traffic; usually not a complete standstill of traffic, so usually not synonymous with traffic jam.  examples

2. (medicine) An excess of mucus or fluid in the respiratory system; congestion of the lungs, or nasal congestion.  examples

3. edema, water retention, swelling, enlargement of a body part because of fluid retention in tissues and vessels  examples