Ectoplasm (noun)

A substance or energy, allegedly emanating from a medium or psychic during a séance, that is said to materialize spirits or form apparitions.

Origin:

From french ectoplasme, from greek ektos (outside) + plasma (something molded or formed).

Examples:

1. The medium claimed to produce ectoplasm during her séances.
2. The ectoplasm was said to be visible only under certain conditions.
3. The ectoplasm was often depicted as a misty or ghostly substance.
4. The existence of ectoplasm has been widely discredited by the scientific community.
5. The appearance of ectoplasm was a common trick used by fraudulent mediums to deceive their audiences.