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

Omnilux’s flexible silicone face mask uses two wavelengths of red and infrared light to target fine lines, wrinkles, and hyperpigmentation. —Conçetta Ciarlo, Vogue, 19 Mar. 2026

The reason astronomers only spotted LRDs after Webb came online is that other telescopes in operation at the time, like Hubble, didn’t have enough resolution or lacked the sensitivity in the longer infrared wavelengths, beyond the threshold of visible light, to see them. —Jacopo Prisco, CNN Money, 17 Mar. 2026

Infrared observations are especially useful for studying molecules hidden inside dusty environments, since different substances absorb light at specific wavelengths that act like unique fingerprints. —Rupendra Brahambhatt, Interesting Engineering, 15 Mar. 2026

After Boogie Nights hitches a ride on the DiCaprio star ascent, a broader audience is able to lock in on Anderson’s wavelength, enough for Magnolia to become a decent-size hit with audiences as well as critics. —Joe Reid, Vulture, 13 Mar. 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