The Collaborative International Dictionary of English v.0.48:

bog \bog\ (b[o^]g), n. [Ir. & Gael. bog soft, tender, moist: cf.
   Ir. bogach bog, moor, marsh, Gael. bogan quagmire.]
   [1913 Webster]
   1. A quagmire filled with decayed moss and other vegetable
      matter; wet spongy ground where a heavy body is apt to
      sink; a marsh; a morass.
      [1913 Webster]

            Appalled with thoughts of bog, or caverned pit,
            Of treacherous earth, subsiding where they tread.
                                                  --R. Jago.
      [1913 Webster]

   2. A little elevated spot or clump of earth, roots, and
      grass, in a marsh or swamp. [Local, U. S.]
      [1913 Webster]

   Bog bean. See Buck bean.

   Bog bumper (bump, to make a loud noise), Bog blitter,
   Bog bluiter, Bog jumper, the bittern. [Prov.]

   Bog butter, a hydrocarbon of butterlike consistence found
      in the peat bogs of Ireland.

   Bog earth (Min.), a soil composed for the most part of
      silex and partially decomposed vegetable fiber. --P. Cyc.

   Bog moss. (Bot.) Same as Sphagnum.

   Bog myrtle (Bot.), the sweet gale.

   Bog ore. (Min.)
      (a) An ore of iron found in boggy or swampy land; a
          variety of brown iron ore, or limonite.
      (b) Bog manganese, the hydrated peroxide of manganese.

   Bog rush (Bot.), any rush growing in bogs; saw grass.

   Bog spavin. See under Spavin.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

buckbean \buckbean\, Buck bean \Buck" bean`\(b[=e]n`). (Bot.)
   A perennial plant (Menyanthes trifoliata) of Europe and
   America which grows in moist and boggy places, having racemes
   of white, reddish, or purplish flowers and intensely bitter
   trifoliate leaves, sometimes used in medicine; marsh trefoil;
   -- called also bog bean. It often roots at the water margin
   and spreads across the surface.

   Syn: water shamrock, bogbean, bog myrtle, marsh trefoil,
        Menyanthes trifoliata.
        [1913 Webster + WordNet 1.5]