morass (n.)
"wet, swampy tract," 1650s, from Dutch moeras "marsh, fen," from Middle Dutch marasch, from Old French marais "marsh," from Frankish, possibly from West Germanic *marisk, from Proto-Germanic *mariskaz "like a lake," from *mari "sea" (see mere (n.)). The word was influenced in Dutch by moer "moor" (see moor (n.)). Figurative use is attested from 1867. Replaced earlier mareis (early 14c.; see marish).