The barred lambda ƛ, (in Unicode U+019B ƛ LATIN SMALL LETTER LAMBDA WITH STROKE), also called running man,[1] is a modified letter of the Greek alphabet used in Americanist phonetic notation to transcribe [t͡ɬ]. It was introduced in American Anthropologist in 1934:
λ for [dl] has been used in Eskimo by Jenness ... ƛ for [tł] is an innovation formed from λ as ł from l.[2]
A barred lambda is used for the affricate [t͡ɬ] in transcribing the Sahaptin language, e.g., iƛúpna ‘he jumped’. It occurs there less frequently than its ejective counterpart, e.g., iƛ’úna ‘he guessed right (in the bone game)’. It is also commonly used to represent this phoneme in several languages of the Caucasus. In addition, its counterpart with a combining comma above right (U+0315), ƛ̕, is used for many of the Salish languages, such as Klallam, for an ejective lateral affricate.
In physics, it is used to represent the angular wavelength, i.e. the wavelength (λ) divided by 2π, which corresponds to the length taken up by one radian of the wave.