ɯ

See also: ա, and Ɯ

ɯ	U+026F, ɯ LATIN SMALL LETTER TURNED M

Character variations

ᵚ	U+1D5A, ᵚ MODIFIER LETTER SMALL TURNED M

Translingual

English Wikipedia has an article on:

Close back unrounded vowel

Wikipedia

ɯ

(IPA) a close back unrounded vowel
(superscript ⟨ᵚ⟩, IPA) [ɯ]-coloring or a weak, fleeting, epenthetic or echo [ɯ].
(superscript ⟨ᵚ⟩, IPA, uncommon) velarization. (More usually ⟨ˠ⟩.)
(UPA) a close central rounded vowel, IPA [ʉ].^[1]

↑ ^1.0 ^1.1 Sovijärvi, Antti, Peltola, Reino (1970) “Suomalais-ugrilainen tarkekirjoitus”, in Helsingin yliopiston fonetiikan laitoksen julkaisuja‎^[1], number 9 (PDF), University of Helsinki, page 12

ɯ (lower case, upper case Ɯ)