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

But there is one surprising behavior where partisans from both ends of the spectrum seem to have more common ground than previously thought: planting trees. —TIME, 22 Apr. 2024

Compared with the previous generation (4G), 5G opens up unused radio frequencies at the high end of the spectrum. —Simon Hill, WIRED, 21 Apr. 2024

Lawmakers across the political spectrum, including Newsom, say lower courts have hindered officials’ ability to regulate encampments at all, causing health and safety issues for the public and people in them. —Gillian Brassil, Sacramento Bee, 20 Apr. 2024

This emerging gap in preferences, cited by five consultants across the political spectrum, has fascinated political observers. —Gerry Shih, Washington Post, 18 Apr. 2024

This includes sources and commentators across the political spectrum — not just the New York Post and Fox News but also PBS, NPR, the New York Times, the Associated Press and Reuters. —Diana Goetsch, Los Angeles Times, 17 Apr. 2024

There was anger, confusion and violence, a full panoply of emotional spectrums played out in that classroom, and simultaneously across the country, riven by equal parts bigotry and hatred, hope and resilience, smiles and tears. —David Baldacci, Peoplemag, 15 Apr. 2024

She was initially diagnosed with schizophrenia spectrum disorder but has been off antipsychotic medications since 2022 with no new symptoms, according to Dr. Ken Robbins, another psychiatrist who believes Geyser is ready to leave Winnebago and has known her since 2014. —CBS News, 11 Apr. 2024

The first of its four Great Observatories was Hubble, launched in 1990, which can perceive in the ultraviolet, visible, and near-infrared regions of the spectrum of electromagnetic energy waves. —Karen Weintraub, USA TODAY, 11 Apr. 2024

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
• on the spectrum
• radio spectrum

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