What is an Eponym?
An eponym as we will use the term here is an ordinary common noun derived from a proper noun, the name of a person or place. Words like quisling, sandwich, and silhouette are solid eponyms. Some eponymous words are still capitalized like a proper noun, so those not capitalized are most clearly eponyms. The important, defining property is that the word does not refer exclusively to the person or place named by the proper noun, as does Marxism or Christian, but is used to refer to a general category, as do quisling, boycott and fuchsias. The ability to undergo inflection such as the plural (Pullmans) is also an indication of the strict eponymous status of a word.