The Collaborative International Dictionary
Fen \Fen\ (f[e^]n), n. [AS. fen, fenn, marsh, mud, dirt; akin to D. veen, OFries. fenne, fene, OHG. fenna, G. fenn, Icel. fen, Goth. fani mud.] Low land overflowed, or covered wholly or partially with water, but producing sedge, coarse grasses, or other aquatic plants; boggy land; moor; marsh.
'Mid reedy fens wide spread.
--Wordsworth.
Note: Fen is used adjectively with the sense of belonging to, or of the nature of, a fen or fens.
Fen boat, a boat of light draught used in marshes.
Fen duck (Zo["o]l.), a wild duck inhabiting fens; the shoveler. [Prov. Eng.]
Fen fowl (Zo["o]l.), any water fowl that frequent fens.
Fen goose (Zo["o]l.), the graylag goose of Europe. [Prov. Eng.]
Fen land, swamp land.