spectral

spectral is an   Adverb

Definition:

[1] Of or pertaining to a specter; ghosty. He that feels timid at the spectral form of evil is not the man to spread light. F. W. Robertson.

[2] Of or pertaining to the spectrum; made by the spectrum; as, spectral colors; spectral analysis. Spectral lemur. (Zoöl.) See Tarsius.

Synonyms: