Alter Ego

alternate personality, second personality

An alter ego (Latin, "the other I") is a second self, a second personality or persona within a person. It was coined in the early nineteenth century when schizophrenia was first described by early psychologists. The term alter ego is commonly used in literature analysis and comparison to describe characters who are psychologically identical, or sometimes to describe a character as an alter ego of the author, a fictional character whose behavior, speech or thoughts intentionally represent those of the author.
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Noun
1. a very close and trusted friend who seems almost a part of yourself
(hypernym) friend

alter ego, alternate personality, second personality

n. alter ego, alternate personality, second personality