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

Thus, observations of a flare in different wavelengths can help better understand the mechanisms black holes use to launch flares and the timescales over which these flares evolve. —Robert Lea, Space.com, 28 Nov. 2025

Interferometry becomes more difficult, however, as the wavelength of light shortens. —Phil Plait, Scientific American, 27 Nov. 2025

Use these light wavelengths with any of the other glow-boosting settings after your skin-care routine for best results. —Emily Orofino, Vogue, 26 Nov. 2025

The team uses its spectroradiometer to capture data across 2,151 wavelength bands from a small spot on a leaf for a reading. —Abhimanyu Ghoshal, New Atlas, 21 Nov. 2025

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