A piranha is a type of fish found in South America, known for its sharp teeth.
Piranhas are often used as an example of something that's extremely aggressive and has a lot of power, but not necessarily as a danger to humans. People might use the word to describe someone or something that's getting a bit out of control, like a piranha that would eat anything in sight if it got loose from its tank.
Any of the carnivorous freshwater fish living in South American rivers and belonging to the subfamily Serrasalminae.
