Placeholder name

Placeholder names are intentionally overly generic and ambiguous terms referring to things, places, or people, the names of which or of whom do not actually exist; are temporarily forgotten, or are unimportant; or in order to avoid stigmatization, or because they are unknowable or unpredictable given the context of their discussion; or to deliberately expunge direct use of the name.

Placeholder names for people are often terms referring to an average person or a predicted persona of a typical user. Provided by Wikipedia