phantom

English phantom comes from Middle English fantome, fanteme, from Old French fantosme, fantasme, from Latin phantasma, from Ancient Greek φάντασμα (phántasma, 'phantasm, an appearance, image, apparition, specter'), itself from φαντάζω (phantázō, 'to make visible').

The Greek root traces back to φαίνω (phaínō), meaning to show or appear, so the word has always been about visibility and appearance before it settled into meaning something unreal or ghostly.

Phantom is a doublet of phantasm — the two English words descend from the same Latin phantasma but arrived by slightly different paths.