The Collaborative International Dictionary of English v.0.48:

Pond \Pond\, n. [Probably originally, an inclosed body of water,
   and the same word as pound. See Pound an inclosure.]
   A body of water, naturally or artificially confined, and
   usually of less extent than a lake. "Through pond or pool."
   --Milton.
   [1913 Webster]

   Pond hen (Zool.), the American coot. See Coot
   (a) .

   Pond lily (Bot.), the water lily. See under Water, and
      Illust. under Nymph[ae]a.

   Pond snail (Zool.), any gastropod living in fresh-water
      ponds or lakes. The most common kinds are air-breathing
      snails (Pulmonifera) belonging to Limn[ae]a, Physa,
      Planorbis, and allied genera. The operculated species are
      pectinibranchs, belonging to Melantho, Valvata, and
      various other genera.

   Pond spice (Bot.), an American shrub (Tetranthera
      geniculata) of the Laurel family, with small oval leaves,
      and axillary clusters of little yellow flowers. The whole
      plant is spicy. It grows in ponds and swamps from Virginia
      to Florida.

   Pond tortoise, Pond turtle (Zool.), any freshwater
      tortoise of the family Emydid[ae]. Numerous species are
      found in North America.
      [1913 Webster]

WordNet (r) 3.0 (2006):

pond lily
    n 1: a water lily having large leaves and showy fragrant flowers
         that float on the water; of temperate and tropical regions
         [syn: water nymph, fragrant water lily, pond lily,
         Nymphaea odorata]