"I suppose you'd know, by now, if you did have to..." Papyrus muses, and studies Cole a little more carefully.

That term has a whole lot of synonyms, and different people already seem to use the same words for very different things. Just listen to the difference between, say, Lambert's monsters - seemingly much closer to the painfully confused and shapeshifted people attacking anyone close to the manor - to Papyrus and Sans and Alphys' monsters! But, well. Spirit sounds like ghost. And there were ghosts back home; probably fine enough folks, aside from the spooky things of turning invisible and floating through walls. How easily they could violate a skeleton's privacy, and he'd never know.