spectrum

noun

spec·​trum ˈspek-trəm 

plural spectra ˈspek-trə  or spectrums

1

a

: a continuum of color formed when a beam of white light is dispersed (as by passage through a prism) so that its component wavelengths are arranged in order

b

: any of various continua that resemble a color spectrum in consisting of an ordered arrangement by a particular characteristic (such as frequency or energy): such as

(1)

: electromagnetic spectrum

(2)

: radio spectrum

(3)

: the range of frequencies of sound waves

(4)

: mass spectrum

c

: the representation (such as a plot) of a spectrum

2

a

: a continuous sequence or range

a wide spectrum of interests

opposite ends of the political spectrum

b

: kinds of organisms associated with a particular situation (such as an environment)

c

: a range of effectiveness against pathogenic organisms

an antibiotic with a broad spectrum

Phrases

on the spectrum

: exhibiting traits associated with autism spectrum disorder

… quiet areas and sensory bags with headphones … and other ways to help kids who are on the spectrum cope with unfamiliar, noisy surroundings.

—Rachel Molenda

… Stephanie Adams, cofounder of the Autism and Asperger's Society, said: "We started the society because we wanted to make a place where people on the spectrum can spend their time and not feel isolated. …"

—Kelsey Maxwell

Synonyms

• diapason
• gamut
• range
• scale
• spread
• stretch

Examples of spectrum in a Sentence

beautiful scarves in all the colors of the spectrum

the complete spectrum of opinions on this hotly debated subject

Recent Examples on the Web

Such mid-career shifts down the defensive spectrum might become more common as defensive evaluation improves — and as teams become more willing to confront their superstars about their flaws — but for now, Devers is a unique case. —Chad Jennings, New York Times, 26 Mar. 2025

Despite being on polar ends of the Meyers-Brigg personality spectrum, the pair settled into a high functioning and lucrative partnership for almost two decades. —Peter Kiefer, HollywoodReporter, 26 Mar. 2025

Lower bounds for middle class income by state Source: U.S. Census Bureau 2021 boundaries , IRS At the other end of the spectrum, Mississippi is the least expensive state to enjoy a middle class lifestyle. —Paul Du Quenoy, MSNBC Newsweek, 26 Mar. 2025

Restoring that and building up a new spectrum pipeline could generate billions for the government, key Republicans say. —Maria Curi, Axios, 24 Mar. 2025

Word History

Etymology

New Latin, from Latin, appearance — more at specter

First Known Use

1672, in the meaning defined at sense 1a

Phrases Containing spectrum

• a broad spectrum
• absorption spectrum
• autism spectrum disorder
• autistic spectrum disorder
• broad-spectrum
• electromagnetic spectrum
• mass spectrum
• radio spectrum

Rhymes for spectrum

• electrum

Kids Definition

spectrum

noun

spec·​trum ˈspek-trəm 

plural spectra -trə  or spectrums

1

a

: the group of different colors including red, orange, yellow, green, blue, indigo, and violet arranged in the order of their wavelengths and seen when white light passes through a prism and falls on a surface or when sunlight is scattered by water droplets to form a rainbow

b

: electromagnetic spectrum

2

: a continuous range or series

a wide spectrum of interests

Medical Definition

spectrum

noun

spec·​trum ˈspek-trəm 

plural spectra -trə  or spectrums

1

a

: a continuum of color formed when a beam of white light is dispersed (as by passage through a prism) so that its component wavelengths are arranged in order

b

: any of various continua that resemble a spectrum in consisting of an ordered arrangement by a particular characteristic (as frequency or energy): as

(1)

: electromagnetic spectrum

(2)

: mass spectrum

c

: the representation (as a plot) of a spectrum

2

: a continuous sequence or range

specifically : a range of effectiveness against pathogenic organisms see broad-spectrum, narrow-spectrum