"clear, open space in a woods," 1529, perhaps from M.E.
glode (c.1300), from O.N.
glaðr "bright" (see
glad). Original meaning would be "bright (because open) space in a wood" (cf. Fr.
clairière "glade," from
clair "clear, bright;" Ger.
Lichtung "clearing, glade," from
Licht "light"). Amer.Eng. sense of "marshy grassland" (e.g.
Everglades) first recorded c.1796.