The Collaborative International Dictionary of English v.0.48:

Froth \Froth\, n. [OE. frothe, Icel. fro[eth]a; akin to Dan.
   fraade, Sw. fradga, AS. [=a]freo[eth]an to froth.]
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   1. The bubbles caused in fluids or liquors by fermentation or
      agitation; spume; foam; esp., a spume of saliva caused by
      disease or nervous excitement.
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   2. Any empty, senseless show of wit or eloquence; rhetoric
      without thought. --Johnson.
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            It was a long speech, but all froth.  --L'Estrange.
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   3. Light, unsubstantial matter. --Tusser.
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   Froth insect (Zool.), the cuckoo spit or frog hopper; --
      called also froth spit, froth worm, and froth fly.


   Froth spit. See Cuckoo spit, under Cuckoo.
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