As the definition for anger mentioned above about the eyebrows is not an operational definition as the eyebrows can come closer or move away in other emotions as well.
Operational definition : Anger is an emotion which is associated with the hostility and aggression where a person shows their displeasure or rage.
Since anger is an intense emotional state it may cause harm to the other people, when one acts aggressively because of frustration.
A man cursing and screaming at his brother is an example of someone displaying anger.
