1having no name or no known name:some pictures were taken by a nameless photographerthe clinic was situated in a little nameless square off James Street
deliberately not identified; anonymous:the director of an organization which shall remain nameless
archaic (of a child) illegitimate:his grandfather had been a nameless, parentless child
2(especially of an emotion) not easy to describe; indefinable:a nameless yearning for transcendence
too horrific to be described:the myths talk about nameless horrors infesting our universe