ec2-18-232-179-37.compute-1.amazonaws.com | ToothyWiki | RecentChanges | Login | Webcomic An adjective describing a character in a literary work for whom the work is named. For example, Dilbert, or JaneEyre. Note that what's-her-name isn't an eponymous heroine of "The Tenant of Wildfell Hall", because the title describes rather than names her.
See also SnowCrash which has a fantastic twist on this naming convention ;)