To lay down a challenge; to provide a test of commitment (often one which carries a high risk) to a cause.
To create a real or artificial boundary or distinction between (two places, people or things).
To indicate the threshold or level above which something will become unacceptable or will provoke a response; to create a boundary and imply or declare that its crossing will provoke a (negative) response.
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.)