Spectrum vs. Spectre

Spectrumnoun

A range; a continuous, infinite, one-dimensional set, possibly bounded by extremes.

Spectrumnoun

Specifically, a range of colours representing light (electromagnetic radiation) of contiguous frequencies; hence electromagnetic spectrum, visible spectrum, ultraviolet spectrum, etc.

Spectrumnoun

The autism spectrum.

Spectrumnoun

(chemistry) The pattern of absorption or emission of radiation produced by a substance when subjected to energy (radiation, heat, electricity, etc.).

Spectrumnoun

The set of eigenvalues of a matrix.

Spectrumnoun

Of a bounded linear operator A, the set of scalar values λ such that the operator A—λI, where I denotes the identity operator, does not have a bounded inverse; intended as a generalisation of the linear algebra sense.

Spectrumnoun

The set, denoted Spec(R), of all prime ideals of a given ring R, commonly augmented with a Zariski topology and considered as a topological space.

Spectrumnoun

(obsolete) Specter, apparition.

Spectrumnoun

The image of something seen that persists after the eyes are closed.

Spectrumnoun

An apparition; a specter.

Spectrumnoun

The several colored and other rays of which light is composed, separated by the refraction of a prism or other means, and observed or studied either as spread out on a screen, by direct vision, by photography, or otherwise. See Illust. of Light, and Spectroscope.

Spectrumnoun

an ordered array of the components of an emission or wave

Spectrumnoun

broad range of related values or qualities or ideas or activities

Spectrum

A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without steps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism.

Spectrenoun

standard spelling of specter|from=British spelling

Spectrenoun

See Specter.

Spectrenoun

a ghostly appearing figure;

Spectrenoun

a mental representation of some haunting experience;

Spectrenoun

a ghost

Spectrenoun

something widely feared as a possible unpleasant or dangerous occurrence