Niek is a female who has anger issues, they like violence, they are sarcastic, and they REALLY hate people. It is common to think of them as assassins in medieval fantasies. It is usually a nickname. Pronounced NEEK.
"Oh my gosh! You are such a Niek! I'm going to start calling you that!"
The one accused of being a Niek, frowned and punched the accuser. "AND I AM NOT VIOLENT!"