1 foam /ˈfoʊm/ noun
1 foam
Learner's definition of FOAM
: a mass of small bubbles that are formed in or on a liquid
: a substance that is like a thick liquid made of many small bubbles
: a soft material that is used to make many products : foam rubber often used before another noun

— foaminess

/ˈfoʊminəs/ noun [noncount]

— foamy

/ˈfoʊmi/ adjective foamier; foamiest
2 foam /ˈfoʊm/ verb
foams; foamed; foaming
2 foam
foams; foamed; foaming
Learner's definition of FOAM
[no object]
: to produce foam

foam at the mouth

: to produce foam from the mouth because of illness or excitement
informal : to be very angry about something