alter ego vs associate

alter ego

noun
  • Somebody'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. 

associate

noun
  • One that habitually accompanies or is associated with another; an attendant circumstance. 

  • A companion; a comrade. 

  • A person united with another or others in an act, enterprise, or business; a partner. 

  • One of a pair of elements of an integral domain (or a ring) such that the two elements are divisible by each other (or, equivalently, such that each one can be expressed as the product of the other with a unit). 

  • Somebody with whom one works, coworker, colleague. 

  • A member of an institution or society who is granted only partial status or privileges. 

verb
  • To connect or join together; combine. 

  • To join as a partner, ally, or friend. 

  • To endorse. 

  • To join in or form a league, union, or association. 

  • To spend time socially; keep company. 

  • To be associative. 

  • To connect evidentially, or in the mind or imagination. 

adj
  • Joined with another or others and having lower status. 

  • Having partial status or privileges. 

  • Following or accompanying; concomitant. 

How often have the words alter ego and associate occurred in a corpus of books? (source: Google Ngram Viewer )