Fen
wetland fed by groundwater and runoff, and containing peat below the waterline. It is, in many ways, intermediate between a bog and a marsh. Fen is an Old English word considered to have proto-Germanic origins, since it has cognates in Gothic, Old Frisian, Dutch and German.
See also the English district of East Anglia called The Fens.
Fen is an invented alternate plural of fan, and is used by science fiction, fantasy, and anime enthusiasts to distinguish themselves from "fans" such as football fans.
FEN is an acronym for Forsyth-Edwards Notation for chess positions.
