wavelength /ˈweɪvlɛŋ(k)θ/noun 2forms 1phrases 1 noun2 •The length of a single cycle of a wave, as measured by the distance between one peak or trough of a wave and the next; it is often designated in physics as λ, and corresponds to the velocity of the wave divided by its frequency.I'd take requests on the telephone / I'm on a wavelength far from home — 1983 •(figurative) A person's attitude and way of thinking as compared to another person's.I think you and I are on a different wavelength. formswavelengths Phrases with wavelength on the same wavelengthThinking in the same way; having similar thought processes (in general).