spectral

adjective

spec·​tral ˈspek-trəl 

1

: of, relating to, or suggesting a specter : ghostly

We felt a spectral presence in the old ballroom.

No ghost stood beside me, nor anything of spectral aspect; merely a motherly, dumpy little woman, in a large shawl, a wrapping-gown, and a clean, trim nightcap.

—Charlotte Brontë

2

: of, relating to, or made by a spectrum

especially : relating to or derived from the electromagnetic spectrum of visible light

Surfaces can differ in the proportion of incident light they reflect (dark ones reflect less than light ones) and in the spectral composition of the light they reflect.

—Principles Of Neural Science

Their examination supported the opinion that the stone was mined in India and cut in London. They also found that the spectral characteristics overlap those of known treated green diamonds.

—Lapidary Journal

spectrally

ˈspek-trə-lē 

adverb

Examples of spectral in a Sentence

Recent Examples on the Web

In experiments, by analyzing the spectral features of these vibropolaritons, the new quantum sensor was able to identify an organic molecule known as 4-mercaptobenzonitrile dissolved in an organic solvent. —IEEE Spectrum, 4 Sep. 2025

Interlune is sending a spectral camera to the moon on an Astrolab rover late this year that will help confirm whether their interpretation of remote imagery of the moon’s geology is correct. —Jeremy Bogaisky, Forbes.com, 2 Sep. 2025

Configurations can include LiDAR, spectral cameras, and thermal imagers. —Kapil Kajal, Interesting Engineering, 2 Sep. 2025

The team also observed the male spectral bat involved in the rearing of his young, according to the study. —Lauren Liebhaber, Miami Herald, 27 Aug. 2025

Word History

First Known Use

1769, in the meaning defined at sense 1

Phrases Containing spectral

• spectral line

Rhymes for spectral

• multispectral

Kids Definition

spectral

adjective

spec·​tral ˈspek-trəl 

1

: of, relating to, or suggesting a specter : ghostly

2

: of, relating to, or made by a spectrum

Medical Definition

spectral

adjective

spec·​tral ˈspek-trəl 

: of, relating to, or made by a spectrum

spectrally adverb