To get ready for a confrontation (debate, argument, fight).
To increase the boxiness of (a design).
To call into question the validity of (a belief, idea, or viewpoint); to challenge.
To portend, or give a warning of.
He threatened me with a knife.
To make a threat against someone; to use threats.
To menace, or be dangerous.
To be close to equaling or surpassing (a record, etc.)