/ kənˈdʒestʃən; NAmE / noun [ U ]
1.
the state of being crowded and full of traffic :
traffic congestion and pollution
2.
( medical ) the state of part of the body being blocked with blood or mucus :
congestion of the lungs
medicine to relieve nasal congestion
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WORD ORIGIN
late Middle English : via Old French from Latin congestio(n-) , from congere heap up, from con- together + gerere bring.