Intimidation (also called cowing) is intentional behavior "which would cause a person of ordinary sensibilities" fear of injury or harm. It's not necessary to prove that the behavior was so violent as to cause terror or that the victim was actually frightened. "The calculated use of violence or the threat of violence to attain goals political, religious, or ideological in nature...through intimidation, coercion, or instilling fear" can be defined as terrorism.

Threatening behaviours are supposed to be a maladaptive outgrowth of normal competitive urge for interrelational dominance generally seen in animals. In case of human com/def/f048.htm]

Like all behavioral traits it exists in greater or lesser manifestation in each individual person over time, but may be a more significant "compensatory behavior" for some as opposed to others. Behavioral theorists often see threatening behaviours as a consequence of being threatened by others, including parents, authority figures, playmates and siblings. “Use of force is justified when a person reasonably believes that it is necessary for the defense of oneself or another against the immediate use of unlawful force.”

Intimidation may be employed consciously or unconsciously, and a percentage of people who employ it consciously may do so as the result of selfishly rationalized notions of its appropriation, utility or self-empowerment. Intimidation related to prejudice and discrimination may include conduct "which annoys, threatens, intimidates, alarms, or puts a person in fear of their safety...because of a belief or perception regarding such person's race, color, national origin, ancestry, gender, religion, religious practice, age, disability or sexual orientation, regardless of whether the belief or perception is correct."

Intimidation may be manifested in such manner as physical contacts, glowering countenance, emotional manipulation, verbal abuse, making someone feel lower than you, purposeful embarrassment and/or actual physical assault. “Behavior may include, but is not limited to, epithets, derogatory comments or slurs and lewd propositions, assault, impeding or blocking movement, offensive touching or any physical interference with normal work or movement, and visual insults, such as derogatory posters or cartoons.”

Criminal threatening is the crime of intentionally or knowingly putting another person in fear of imminent bodily injury. “Threat of harm generally involves a perception of injury...physical or mental damage...act or instance of injury, or a material and tangible detriment or loss to a person.” “A terroristic threat is a crime generally involving a threat to commit violence communicated with the intent to terrorize another.”

There is no legal definition in English law as to what behaviour constitutes "Intimidation", so it is up to the courts to decide on a case by case basis. However, if somebody threatens violence against somebody, then this may be a criminal offence.