Noun

(en-noun)

Specter, apparition.

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

* {{quote-news, year=2012, date=November 7, author=Matt Bai, title=Winning a Second Term, Obama Will Confront Familiar Headwinds, work=New York Times citation

, passage=As Mr. Obama prepared to take the oath, his approval rating touched a remarkable 70 percent in some polling — a reflection of good will across the political spectrum .}}

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

* 2010 October 30, Jim Giles, Jammed!'', in '' ,

Current 3G technologies can send roughly 1 bit of data - a one or a zero - per second over each 1 Hz of spectrum that the operator owns.

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

(mathematics, linear algebra) The set of eigenvalues of a matrix.

(mathematics, functional analysis) Of a bounded linear operator A'', the set of scalar values ? such that the operator ''A—?I'', where ''I denotes the identity operator, does not have a bounded inverse; intended as a generalisation of the linear algebra sense.

Noun

(en noun)

A sequence of gradual, successive stages; a systematic progression.

A passing by small degrees from one tone or shade, as of color, to another. See Synonyms at nuance.

The act of gradating or arranging in grades.

Any degree or relative position in an order or series.

* I. Taylor

the several gradations of the intelligent universe

(countable) A calibration marking.

(music) A gradual change within one parameter, or an overlapping of two blocks of sound.

(phonetics) Apophony.