Wavelength

Part of speech: noun

Pronunciation: /ˈweɪvlɛŋ(k)θ/

Definitions

1. The distance between successive crests of a wave, or the specific range of light that determines its color
2. The interval from one crest of a wave to the next defines the distance that influences both sound and light, dictating the frequency and color of electromagnetic radiation
3. The measurable space between two consecutive wave crests, which affects the characteristics of sound and light, including their colors and frequencies

Etymology: "Wavelength" is a plain compound of "wave" and "length," with no foreign roots or disputed history behind it. "Wave" comes from Old English "wæg," and "length" from Old English "lengthu," a noun formed from "long." Put together, the literal sense is simply the length of a wave, measured from one crest to the next. The modern scientific meaning grew out of that everyday picture. Physicists applied the term to light and other electromagnetic radiation, where the wavelength determines the frequency and, for visible light, the colour a person perceives. The compound is transparent in a way many scientific words are not: a reader can usually work out its meaning from its two parts, which is why it has changed little since it entered technical use.

Synonyms: frequency, wave length