second self


noun

one who associates so closely with a given person as to assume that person's mode of behavior, personality, beliefs, etc.

Origin of second self

First recorded in 1580–90
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for second self

  • Was it his counterpart, or second-self, that made him feel that evening as though he had never known himself?

    Dawn|Mrs. Harriet A. Adams