Source : Webster's Revised Unabridged Dictionary (1913)

Frog \Frog\ (fr[o^]g), n. [AS. froggu, frocga a frog (in
   sensel); akin to D. vorsch, OHG. frosk, G. frosch, Icel.
   froskr, fraukr, Sw. & Dan. fr["o].]
   1. (Zo["o]l.) An amphibious animal of the genus {Rana} and
      related genera, of many species. Frogs swim rapidly, and
      take long leaps on land. Many of the species utter loud
      notes in the springtime.

   Note: The edible frog of Europe ({Rana esculenta}) is
         extensively used as food; the American bullfrog ({R.
         Catesbiana}) is remarkable for its great size and loud
         voice.

   2. [Perh. akin to E. fork, cf. frush frog of a horse.]
      (Anat.) The triangular prominence of the hoof, in the
      middle of the sole of the foot of the horse, and other
      animals; the fourchette.

   3. (Railroads) A supporting plate having raised ribs that
      form continuations of the rails, to guide the wheels where
      one track branches from another or crosses it.

   4. [Cf. fraco of wool or silk, L. floccus, E. frock.] An
      oblong cloak button, covered with netted thread, and
      fastening into a loop instead of a button hole.

   5. The loop of the scabbard of a bayonet or sword.

   {Cross frog} (Railroads), a frog adapted for tracks that
      cross at right angles.

   {Frog cheese}, a popular name for a large puffball.

   {Frog eater}, one who eats frogs; -- a term of contempt
      applied to a Frenchman by the vulgar class of English.

   {Frog fly}. (Zo["o]l.) See {Frog} hopper.

   {Frog hopper} (Zo["o]l.), a small, leaping, hemipterous
      insect living on plants. The larv[ae] are inclosed in a
      frothy liquid called {cuckoo spit} or {frog spit}.

   {Frog lily} (Bot.), the yellow water lily ({Nuphar}).

   {Frog spit} (Zo["o]l.), the frothy exudation of the {frog
      hopper}; -- called also {frog spittle}. See {Cuckoo spit},
      under {Cuckoo}.