Piranha (noun)

1. A freshwater fish found in South American rivers, known for its sharp teeth and aggressive behavior.
2. A person or group that is perceived as dangerous or ruthless in their pursuit of something.

Origin:

Piranha comes from the tupi word "pira" meaning "fish" and "ñaha" meaning "tooth".

Examples:

1. The piranhas in the river were feared by the locals.
2. He was a real piranha in the boardroom.
3. Piranhas are known for their razor-sharp teeth.
4. The piranhas quickly devoured the fish.
5. The piranhas were a formidable enemy for the fishermen.