Eponym

n. person whose name is used as the name of a place or thing; medical name of a disease derived from a person's name; ancient official whose name was used to indicate the year he was in office

An eponym is the name of a person, whether real or fictitious, who has (or is thought to have) given rise to the name of a particular place, tribe, era, discovery, or other item. An eponymous person is the person referred to by the eponym. In contemporary English, the term eponymous is often used to mean self-titled. The word eponym is often used for the thing titled. Stigler's law of eponymy suggests that Eponyms are usually false, i.e., things are rarely named after the person who discovered or invented them. An aitiology is a "reverse eponym" in the sense that a legendary character is invented in order to explain a term.
See more at Wikipedia.org...

Noun
1. the name of a person for whom something is supposedly named; "Constantine I is the eponym for Constantinople"
(hypernym) name
2. a name derived from the name of person (real or imaginary) as the name of Alexandria is derived from the name of its founder: Alexander the Great
(hypernym) name

(n.)
Alt. of Eponyme
  

Something named after someone. For example, a condition called Shiel’s syndrome might be named after someone named Shiel who discovered it or described and clearly delineated it.