A phantom, a ghost or elusive entity.
An image or representation of an idea; a representation of an ideal form; an apparition of some actual or imaginary entity, or of some aspect of reality.
An unsubstantial image, spectre, phantom.
A ghost, deity or other supernatural entity.
A wraith-like creature.
A being of one of the Nine Worlds of Heathen belief, especially a nature spirit, elf or ancestor.