who's who

Meanings

1. A publication containing biographies of well-known or important people.
2. A list of notable, famous, or upper-class people.
3. Collectively, the elite class.
4. A person appearing in a Who's Who publication.
5. A celebrity or famous person, someone likely to be in such a publication.
6. The identities of specific people, understood in terms of such distinguishing characteristics as their backgrounds, prominence, achievements, jobs, etc., as a basis for comparing them and especially as a basis for ranking them within a social group.

1. Alternative form of who's who.

Etymology

From Who's Who, the British publication of biographies for the upper class, first published in 1849.