wavelength

noun

wave·​length ˈwāv-ˌleŋ(k)th 

1

: the distance in the line of advance of a wave from any one point to the next point of corresponding phase

2

: a particular course or line of thought especially as related to mutual understanding

two people on different wavelengths

Examples of wavelength in a Sentence

Light and sound have different wavelengths.

Recent Examples on the Web

These images of the corona and solar prominences were taken in different wavelengths of visible and infrared light by imagers aboard a NASA’s WB-57 jet during the April 8, 2024, total solar eclipse. — Jamie Carter, Forbes.com, 1 Aug. 2026

The Wrinkle Retreat light therapy mask combines four wavelengths to support visibly fewer fine lines and wrinkles. — ABC News, 1 Aug. 2026

Photons of different infrared wavelengths and intensities excite different electronic transitions, moving an electron between discrete energy levels within the dot, rather than just producing more or less of a single signal. — Jacek Krywko, ArsTechnica, 31 July 2026

Green light has a shorter wavelength than red light, targeting skin concerns in the superficial layers, such as hyperpigmentation (dark spots) and inflammation. — Sarah Bence, Verywell Health, 29 July 2026

Word History

First Known Use

1850, in the meaning defined at sense 1

Kids Definition

wavelength

noun

wave·​length ˈwāv-ˌleŋ(k)th 

1

: the distance (as from crest to crest) in the line of advance of a wave from any one point to the next corresponding point

2

: a certain line of thought or behavior that reveals a common understanding

coworkers who are on the same wavelength

Medical Definition

wavelength

noun

wave·​length -ˌleŋ(k)th 

: the distance in the line of advance of a wave from any one point to the next point of corresponding phase

—symbol λ