spectral
Of, or pertaining to, spectres; ghostly.
Example
“The spectral chain-rattling and moans gave me the chills.”
Other meanings
Of, or pertaining to, spectra; classified according to frequency or wavelength (of light, etc.).
on the spectrum; spectrumy.
Where this comes from
This definition is adapted from “spectral” on Wiktionary, by its contributors, published under CC BY-SA 4.0. This page is published under the same licence.