wavelength

American  

[weyv-lengkth, -length, -lenth] / ˈweɪvˌlɛŋkθ, -ˌlɛŋθ, -ˌlɛnθ /

Or wave length

noun

1. Physics. the distance, measured in the direction of propagation of a wave, between two successive points in the wave that are characterized by the same phase of oscillation.

---

idioms

1. on the same wavelength, in sympathy or rapport.

   We seemed to be on the same wavelength from the moment we met.

wavelength British  

/ ˈweɪvˌlɛŋθ /

noun

1.  λ.  the distance, measured in the direction of propagation, between two points of the same phase in consecutive cycles of a wave

2. the wavelength of the carrier wave used by a particular broadcasting station

3. informal having similar views, feelings, or thoughts (as someone else)

---

wavelength Scientific  

/ wāv′lĕngkth′ /

1. The distance between one peak or crest of a wave and the next peak or crest. It is equal to the speed of the wave divided by its frequency, and to the speed of a wave times its period.

---

wavelength Cultural  

1. The distance between crests (or troughs) of a wave.

---

Etymology

Origin of wavelength

First recorded in 1855–60; wave + length

Explanation

A wavelength is the distance between two peaks in a wave. And, if you are on the same wavelength with someone else, you are in sync and share the same perspective. You can say, "My best friend and I are on the same wavelength," meaning you truly understand each other and tend to see the world in the same way. This meaning has been around since the 1920s, but originally wavelength had only its scientific definition, "the distance between two peaks of a wave." Wavelengths can be measured on anything that travels in waves, like sound, light, or water. The Old English root word is wagian, "to move back and forth."

Example Sentences

This wavelength lies beyond the deepest red that humans can normally see.

From Science Daily • Apr. 9, 2026

Black is the absorption of light; white is the presence of every wavelength.

From The Wall Street Journal • Mar. 27, 2026

The enhanced field is directly accessible to surface materials, the resonant wavelength can be tuned by adjusting the cavity shape, and the design remains effective even in materials that strongly absorb light.

From Science Daily • Mar. 24, 2026

This effectively compressed the light into a region much smaller than its wavelength, allowing it to bypass the diffraction limit and reveal much finer details.

From Science Daily • Mar. 17, 2026

So you have a bunch of regularly-spaced waves that are trapped, bouncing back and forth in a container that fits their wavelength perfectly.

From "Understanding Basic Music Theory" by Catherine Schmidt-Jones and Russel Jones

Related Words

• acumen
• intuition
• judgment
• observation
• understanding
• vision
• wisdom