(For s.t.) to make bubbles or suds; to foam [N-]; (for s.o.) to make bubbles or suds [ma-]. [When soapsuds are the topic, "ngappu'" is used more often than "ngalappu'"].
That person's mouth foams when he has an epileptic attack.
Soap will not make suds if salt water is used for washing clothes.
Don't allow your child to make suds from powdered soap if he isn't washing clothes.