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

Blue-wavelength light tells the brain to suppress melatonin and stay sharp. —Allison Palmer june 2, Fort Worth Star-Telegram, 2 June 2026

Earth’s atmosphere scatters shorter blue wavelengths more efficiently, allowing warmer red and orange tones to dominate — the same effect that produces vivid sunsets. —Jamie Carter, Forbes.com, 30 May 2026

This light has a very specific wavelength, or color, but the JWST observations showed a minuscule shift in this color from one end of the maelstrom to the other because of the hydrogen’s motion. —Joseph Howlett, Scientific American, 27 May 2026

During a process called Rayleigh scattering, shorter blue wavelengths scatter, causing the moon to appear orange or reddish. —Olivia McIntosh, Martha Stewart, 27 May 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