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

Specifically, this image was captured by JWST's NIRCam (Near-InfraRed Camera) instrument, which peers into the near-infrared, a wavelength range that encompasses the light from faint stars and galaxies. — Chelsea Gohd, Space.com, 7 Oct. 2026

At-home red light devices stimulate follicles with specific wavelengths. — Hanna Wickes, Miami Herald, 7 Oct. 2026

Not only cozy in a visual sense but also effective in all the ways 670nm red light is effective (this wavelength is known to promote melatonin production), the bedroom and nursery nonnegotiable is 20 percent off for a limited time only. — Stacia Datskovska, Footwear News, 6 Oct. 2026

Researchers developed LEDs that emit UVC at wavelengths below 235 nm, which is also absorbed by the outer, non-living layers of the skin. — Ameya Paleja, Interesting Engineering, 1 Oct. 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