What is the meaning of Alter_ego?

An individual's alternate personality or persona; another self.

A very close and intimate friend.

A corporation used by a person to conduct personal business in an attempt to shield himself or herself from personal liability, and which a court may penetrate by "piercing the corporate veil" to impose liability on the person when they commit fraud or injustice.

alter ego

alter ego (somebody's alternate personality or persona)

alter ego (individual's alternate personality or persona; another self)

alter ego (alternate personality or persona)

alter ego (alternate personality or persona)

Source: wiktionary.org