Intimidate is a Social Action in which a character brings to bear every forceful stance, glare, and affectation they can against a target in order to get the target to back down, stop advancing, and/or prevent them from taking a dangerously hostile action on the character.
A character can bring their Charisma to bear, with either theatrics (positive) or crassness (negative) both having an equal impact. In certain settings, certain signs, symbols, institutional displays, social status displays, and equipment can add to the effectiveness of trying to intimidate a target.