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

The wavelengths most commonly cited in this category are 630 nanometers for red light and 830 nanometers for near-infrared, the same pairing L'Oréal is using in its new flexible LED face mask. —Allison Palmer updated June 24, Fort Worth Star-Telegram, 24 June 2026

Skip TikTok Shop dupes that don’t publish wavelength or irradiance numbers. —Allison Palmer updated June 24, Kansas City Star, 24 June 2026

As the universe has expanded in the time since then, the ultraviolet light has been redshifted into visible wavelengths that were detected by Hubble. —Keith Cooper, Space.com, 24 June 2026

To precisely print transistors at these infinitesimal scales, light with an incredibly short wavelength must be used. —Rob Toews, Forbes.com, 22 June 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