U0110400 (ŭn-round′)tr.v.un·round·ed, un·round·ing, un·rounds To pronounce (a sound) with the lips in a flattened or neutral position.
unround
(ʌnˈraʊnd) adjnot roundvb (tr) (Linguistics) to release (lips) from a rounded position, esp in pronunciation
un•round
(ʌnˈraʊnd)
v.t. 1. to articulate (an ordinarily rounded vowel) without rounding the lips. 2. to extend (the lips) laterally in a spread or neutral position. [1605–15]