Emily Dickinson Lexicon

SWAMP, n. [Sax. swam, a fungus or mushroom; Goth. swamms, a spunge, G. schwamm, D. zwam, Dan. svamp; Sw. id. a spunge, a fungus.]

Spungy land; low ground filled with water; soft wet ground. In New England, I believe this word is never applied to marsh, or the boggy land made by the overflowing of salt water, but always to low soft ground in the interior country; wet and spongy land, but not usually covered with water. This is the true meaning of the word. Swamp are often mowed. In England, the word is explained in books by boggy land, morassy or marshy ground.