Emily Dickinson Lexicon

BOG, n. [Ir. bog, soft; bogach, a marsh; bogha, a bow; boghaim, to bend; Sax. bugan; D. boogen, to bend. Soft is flexible, yielding to pressure, bending. See Bow.]

1. A quagmire covered with grass or other plants. It is defined by marsh and morass, but differs from a marsh, as a part from the whole. Wet grounds are bogs, which are the softest and too soft to bear a man; marshes or fens, which are less soft, but very wet; and swamps, which are soft spungy land, upon the surface, but sustain man and beast, and are often mowed.
2. A little elevated spot or clump of earth, in marshes and swamps, filled with roots and grass. [This is a common use of the word in New England.]