spectrum

noun

spec·​trum ˈspek-trəm How to pronounce spectrum (audio)
plural spectra ˈspek-trə How to pronounce spectrum (audio) 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
(3)
: the range of frequencies of sound waves
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

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The palette reflects the spectrum of summer evenings, Fatih Kesim, the mill’s general manager, said, featuring hues of cacao, marsala, blue, and grey. Angela Velasquez, Sourcing Journal, 16 Oct. 2025 Changes in routine can be challenging, however, especially for families with kids on the autism spectrum. Nathan Diller, USA Today, 16 Oct. 2025 Cate’s response, along with the other characters, all come across as representing a different facet of the emotional spectrum of the grief process. Abbey White, HollywoodReporter, 16 Oct. 2025 Or go on the opposite side of the design spectrum and wake up your coffee party with an Anut Cairo Circus jar—a perfect place to stash sugar cubes. Yelena Moroz Alpert, Architectural Digest, 15 Oct. 2025 See All Example Sentences for spectrum

Word History

Etymology

New Latin, from Latin, appearance — more at specter

First Known Use

1672, in the meaning defined at sense 1a

Time Traveler
The first known use of spectrum was in 1672

Browse Nearby Words

Cite this Entry

“Spectrum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/spectrum. Accessed 17 Oct. 2025.

Kids Definition

spectrum

noun
spec·​trum ˈspek-trəm How to pronounce spectrum (audio)
plural spectra -trə How to pronounce spectrum (audio) 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
2
: a continuous range or series
a wide spectrum of interests

Medical Definition

spectrum

noun
spec·​trum ˈspek-trəm How to pronounce spectrum (audio)
plural spectra -trə How to pronounce spectrum (audio) 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
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

More from Merriam-Webster on spectrum

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!