Threat

A threat is the communication to a person of the intent of violence (which may or may not be aggression) against that person. Stephan Kinsella has argued that there are limits to how useful armchair reasoning about hypothetical threats can be.

Game Theory
In game theory a threat is a response rule that punishes others who fail to cooperate with you. It is a strategic move in the sense that it limits the options of the person making the threat and creates control in a situation, compelling another to cooperate.