An alter ego is defined as another version of oneself.(noun)
An example of an alter ego is a person who behaves almost as similarly to you, your differences are unrecognizable.
The definition of an alter ego is someone with whom you are very close friends.(noun)
An example of an alter ego is someone with whom you have been friends since childhood.
See alter ego in Webster's New World College Dictionary
Origin: L, lit., other I
See alter ego in American Heritage Dictionary 4
Origin: : alter, other
Origin: + ego, I, self.
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