# spectrum

/ˈspɛktɹəm/ (US) · /spˈɛktɹəm/ (UK)

Source: https://englishreference.com/word/spectrum
Updated: 2026-06-19

## Senses

### 1. a range of ideas or things

noun · CEFR B2

a wide range of different opinions, people, or ideas that are related to each other.

For teachers: a broad range of varied but related ideas or objects, often positioned between two opposite points.

- The political spectrum includes many different views from the left to the right.
- The survey captured a broad spectrum of public opinion, ranging from enthusiastic support to deep-seated skepticism regarding the new policy.

### 2. light and colours

noun · CEFR B2

the set of colours you see when light passes through a prism, like a rainbow.

For teachers: the distribution of colors produced when light is dispersed by a prism or similar device.

- A prism breaks white light into the visible spectrum of colours.
- Astronomers analyze the star's light spectrum to determine its chemical composition and temperature.

### 3. neurodiversity

noun · CEFR B2

a way of describing a range of conditions, especially autism, that affect how people think and behave.

For teachers: a range of conditions or symptoms, specifically used to describe the variety of ways autism manifests in individuals.

- Because autism is a spectrum, every person has different strengths and challenges.
- Clinicians now recognize that these behaviors exist on a spectrum rather than being distinct, unrelated disorders.

### 4. mathematical eigenvalues

noun · CEFR C2 · Technical

a special set of numbers related to a square grid of numbers called a matrix.

For teachers: the set of eigenvalues of a matrix or, more generally, of a bounded linear operator.

- The professor asked us to calculate the spectrum of the given matrix.
- In functional analysis, the spectrum of an operator generalizes the concept of eigenvalues for finite-dimensional matrices.

### 5. a ghost

noun · CEFR C2 · Archaic · Literary

an old word for a ghost or a strange vision.

For teachers: a phantom, ghost, or apparition; the Latin root of the modern word.

- The old story spoke of a spectrum that haunted the castle halls.
- The poet described a pale spectrum rising from the mist, a lingering shadow of a forgotten era.

## Examples

- The school offers a wide spectrum of classes.
- Politicians from across the political spectrum agreed that the new law would help small businesses grow.
- The research project aims to capture a broad spectrum of opinions by interviewing people from diverse socioeconomic backgrounds and age groups across the entire country.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.