a mass of small bubbles, especially on the surface of a liquid

ideas, activities, etc. that seem attractive and fun but have no real value

something that looks like a mass of small bubbles on liquid

if a liquid froths, or if somebody/something froths it, a mass of small bubbles appears on the surface

to produce a lot of saliva(= liquid in your mouth)

The dog was frothing at the mouth.

(figurative)He frothed at the mouth when I asked for more money.

LEARNit Dictionary