congestion (n.)youdaoicibaDictYouDict[congestion 词源字典]
early 15c., "action of gathering together," from Middle French congestion (14c.), from Latin congestionem (nominative congestio), noun of action from past participle stem of congerere (see congest). Medical sense is from 1630s; meaning "a crowding together of people, traffic, etc." is from 1883.[congestion etymology, congestion origin, 英语词源]