Open
开唇
Open is used in the classification of lip positions, referring to the visual appearance of the lips when they are held relatively wide apart, but without any noticeable rounding, as in such sounds as the /a/ in part.
给唇位分类的术语,指双唇看上去持张开较大的姿势,无明显的圆唇,如发part“部分”中的/a/音。