froth froth /ˈfrɔθ/

noun

1. () A mass of small bubbles formed in or on a liquid  ( froth , foam )
   a mass of small bubbles formed in or on a liquid
    The beer had a thick head of foam
   the beer had a thick head of foam
   
   

verb

1. Exude or expel foam  ( froth )
   exude or expel foam
    The angry man was frothing at the mouth
   the angry man was frothing at the mouth
   
2. Make froth or foam and become bubbly  ( froth , spume , suds [ N. American] )
   make froth or foam and become bubbly
    The river foamed
   The river foamed
   
3. Become bubbly, frothy or foaming  ( effervesce , fizz , form bubbles , foam , froth , sparkle )
   become bubbly, frothy or foaming
    The boiling soup was frothing
   The boiling soup was frothing
    The river was foaming
   The river was foaming
    Sparkling water
   sparkling water