Of, relating to, or comprising the Indo-European languages that maintained a distinction between the reflexes of Indo-European velar k, g, gh and labiovelar kw, gw, gwh.

• 颚音类的保留了软颚音k、g、gh与圆唇软颚音kw，gw，gwh。之间反映形式区别的印欧语系语言的、与之相关的或由之组成的