Small voraciously carnivorous freshwater fishes of South America that attack and destroy living animals(noun)
WordNet. Princeton University. 2010.
Use "pirana" in a sentence
"And those of us who do our best to raise mindful, empathic, self-regulated individuals have to throw them into the pirana pool at some point in their tender lives."
"No science fiction convention, no pimping art, no pirana puppy."
"Sheesh: If you are going to risk your career, wouldn't you find something less, pirana-like, to blow it on?"