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

But the vastness was really about fostering conditions in which his spectral harmonies could thrive. —Alex Ross, New Yorker, 26 Jan. 2026

The series stars Jared Harris as Francis Crozier as captain of the HMS Terror and Tobias Menzies as James Fitzjames, captain of the HMS Erebus, whose crews are stalked by a spectral creature called a Tuunbaq after the ships are trapped in the ice. —David Faris, TheWeek, 23 Jan. 2026

With this media, tuning the write laser frequency to match that of one of the nano-particle frequencies creates a spectral hole where the nanoparticle emission can be diminished as shown in (b) in the figure below. —Thomas Coughlin, Forbes.com, 21 Jan. 2026

Using real-time spectral analysis inspired by George Lewis’s Voyager, the instrument generates its own musical responses to create a non-hierarchical duet between the performer’s physical gestures and the machine’s digital brain. —Andrew Paul, Popular Science, 21 Jan. 2026

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