Notan. Royal Psychologist of Zodanga.
Nutus. Jeddak of Dusar.
Od. Martian foot.
Odwar. A commander, or general.
Okar. Land of the yellow men.
Old Ben (or Uncle Ben). The writer’s body-servant (coloured).
Omad. Man with one name.
Omean. The buried sea.
Orluk. A black and yellow striped Arctic monster.
Otz Mountains. Surrounding the Valley Dor and the Lost Sea of Korus.