I would imagine most people who have heard of ectoplasm associate it with the slime from Ghostbusters. Peter Venkman, played by Bill Murray, got covered with it during a run-in with the green spud Slimer, you may recall. (Earlier in the film, he was tasked with collecting a sample of ectoplasm by fellow ghostbuster Egon Spengler, prompting Venkman to quip, “Somebody blows their nose and you want to keep it.”)
Ectoplasm, however, really exists. It’s a particular type of cytoplasm in amoebas, one-celled organisms that move about by altering their shape (in arguably ghost-like fashion, I suppose).
Cytoplasm is one of those words that is its own definition. It’s the stuff that surrounds the nucleus inside cells.
Back in the realm of the paranormal, ectoplasm was also a big concern for spiritualists in the late 19th and early 20th centuries. Spirit photographers claimed they could photograph ectoplasm, often emanating from a medium supposedly communing with the dead. Perhaps these pictures were convincing at the time, but now the ghostly ectoplasm looks like the cotton fluff or paper it usually was. Special effects have come a long way since then.