Eponymous (adjective)

1. Giving one's name to a thing or a person, such as a place, a tribe, or an era.
2. Being the person or thing for whom or which something is named.

Origin:

From the greek word eponymos, which means "giving one"s name to".

Examples:

1. The city was eponymous with the founder's name.
2. The tribe was eponymous with the leader's name.
3. The era was eponymous with the ruler's name.
4. The character in the book is eponymous with the protagonist.
5. The disease was eponymous with the doctor who discovered it.