Simple past tense and past participle of decongest.(verb)
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Use "decongested" in a sentence
"I'm usually pretty decongested after the sneezing fit."
"So while we may not end this economic downturn with a slew of new parks and pools, we could end up with other unexpected benefits: for example, completely public wireless Internet access; a shorter commute on newly decongested highways; or, for those who live in cities, subway cars that aren't so crowded."
"Most central business districts were now decongested, "clean and peaceful", and crime had gone down by 25 percent."