Definition of congests:
(v) :
(transitive) To hinder or block the passage of something moving, 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.
(v) :
(intransitive) To become blocked or obstructed
(n) :
(Ireland, Scotland, agriculture, history) A farmer whose lands do not support him adequately.