noun

congestion

kun-JES-chun/kənˈdʒestʃən/

Excessive accumulation that impedes normal flow.

Heavy traffic congestion keeps the buses from arriving on time.

A bottleneck of closely packed vehicles blocks a short intersection while the road beyond is clear, showing slowed flow caused by overcrowding.

Etymology

conLatintogether

+gestLatinto carry

+ionLatinaction or process

The pieces describe a “carrying together,” hence a heaping up. Congestion first referred to accumulated matter in the body; the same buildup image later extended to crowds and traffic that impede movement.

In context

London Review Bookshop44:36

there was much less road rage, much less congestion, and the traffic flowed better

Adam Phillips and Chris Oakley: Unforbidden Pleasures

More examples

A saline spray helps relieve her nasal congestion.
Opening another entrance reduces congestion near the ticket booth.
Network congestion slows downloads during peak hours.

Forms

congestion

congest verb — To block or hinder through excessive accumulation.

congested adjective — Overcrowded or blocked by an excessive buildup.

Similar words

overcrowding: Emphasizes too many people or things in limited space.
blockage: Emphasizes an obstruction, not necessarily an excessive accumulation.
bottleneck: Identifies a narrow point that limits overall flow.