As a verb overcrowded
As an adjective overcrowded
is containing too many occupants for an area of its size.
As a noun congestion is
Containing too many occupants for an area of its size.
The act of gathering into a heap or mass; accumulation.
An excess of traffic.
(medicine) Overfullness of the capillary and other blood vessels, etc., in any locality or organ (often producing other morbid symptoms); local hypermic, active or passive; as, arterial congestion; venous congestion; congestion of the lungs.
(medicine) An excess of mucus or fluid in the respiratory system; congestion of the lungs, or nasal congestion.
* congestion charge or congestion pricing