The Collaborative International Dictionary of English v.0.48:

Frogs-bit \Frog"s`-bit"\, n. (Bot.)
   Frogbit.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

frogbit \frog"bit`\, frog's-bit \frog's-bit\, n. (Bot.)
      (a) A European plant (Hydrocharis Morsus-ran[ae]),
          floating on still water and propagating itself by
          runners. It has roundish heart-shaped leaves and small
          white flowers.
      (b) An American plant (Limnobium Spongia), with similar
          habits.
          [1913 Webster]