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 many cases, physicists can calculate the spectral gap for a specific atom or material. —Charlie Wood, Wired News, 6 Apr. 2025

And by scouring the planets’ atmospheres, astrobiologists hoped to search for the spectral fingerprints of life. —Elise Cutts, Quanta Magazine, 12 Mar. 2025

The ever-growing pool of EO data lacks consistency in spectral reflectance, which in turn creates major issues for data scientists. —Elizabeth Duffy, Forbes, 11 Mar. 2025

Limited Spectral Diversity: Many current EO datasets lack the spectral diversity needed for nuanced insights, which reduces AI’s ability to detect subtle variations in land use, vegetation health and environmental changes. —Elizabeth Duffy, Forbes, 11 Mar. 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