What’s the plural of “spectrum”?
The plural of spectrum is spectra or spectrums. A spectrum, which is “a range of different positions, opinions, etc. between two extreme points”, originally comes from Latin and uses the standard Latin suffixes from singular to plural. Latin nouns that end in -um as a singular switch to -a as a plural (e.g., referendum/referenda, memorandum/memoranda).
The different spectra of light were visible through the prism.
The report identified a single worrying phenomenon.
This curious phenomena has baffled scientists for years.
We observed various spectras in the lab results.
What’s the singular of spectrum?
Spectrum is singular of spectra or spectrums.
What does the word spectrum mean?
The word spectrum is understood as “a range of different positions, opinions, etc. between two extreme points”. For example: He has support from across the whole political spectrum. The group includes students from both ends of the social spectrum (= range of social classes).
Other Latin nouns in English
| singular | plural |
|---|---|
| phenomenon | phenomena or phenomenons |
| criterion | criteria |
| bacterion | bacteria |
| medium | media |
| datum | data |
| spectrum | spectra or spectrums |
The plural of “spectrum,” think of the word “spectra” as a musical term, like “octaves” or “harmonies,” which both have multiple parts.
“Spectrum”, used in sentences
3. He was held in great affection by people from the entire political spectrum.
4. He is some way along the autistic spectrum.
5. My disease is nowhere near as bad as hers but they are on the same spectrum.
“Spectrums”/”spectra”, used in sentences
1. Let us look at some examples of spectra.
2. The spectra of the metals of the alkaline earths are equally definite, though more complicated.
3. It is science when the astronomer compares the spectrum of the sun with the spectra of various metals in the laboratory.
4. Commanders on the ground could call up the images they wanted, in the spectra they wanted – visible, infrared, UV, whatever. Michael Crichton. PREY. (2002).
5. Spectra flowing through the prism appeared as bright as bands of rainbow colored light.
Origin of the word spectrum
From etymology online on spectrum (n.):
1610s, “apparition, specter,” from Latin spectrum (plural spectra) “an appearance, image, apparition, specter,” from specere “to look at, view”.
Read more about nouns
| Types of nouns | What’s the plural of …? |
|---|---|
| plural-only nouns | …moose? |
| mass nouns | …octopus? |
| collective nouns | …cactus? |
| abstract nouns vs. concrete nouns | …analysis? |
| possessive nouns | …curriculum? |
| regular and irregular nouns | …crisis? |
Sources
- Definition of spectrum.
- Sentences using spectrum.
- Origin of spectrum.
Work Sheet
According to the blog post, what are the accepted plural forms of “spectrum”?
Which of the following is the original Latin plural form of “spectrum” mentioned in the post?
The blog post notes that Latin nouns ending in -um in the singular typically form their plural by changing the ending to:
Which of the following is indicated in the post as an incorrect plural form of “spectrum”?
Based on the definition provided in the post, what does the word “spectrum” primarily refer to?
The different ______ of light were visible through the prism.
The survey revealed a wide ______ of opinion.
Scientists studied the various energy ______ emitted by the element.
Using the plural form of ‘phenomenon’ as a singular noun is incorrect; for example, you should not say ‘This curious ______ has baffled scientists’.
The committee included members from both ends of the social ______.
Frequently Asked Questions
What is the plural of spectrum?
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Is “spectras” the plural form?
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What is the singular of spectra?
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Why is “spectra” a plural option?
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Can you use spectra in a sentence?
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Yash, D. "What’s the Plural of Spectrum?." Grammarflex, Jun 21, 2025, https://www.grammarflex.com/whats-the-plural-of-spectrum/.
