Unintelligible language is impossible to understand, for example because it is not written or pronounced clearly, or because its meaning is confused or complicated.
例句
He muttered something unintelligible...他嘴里不知咕哝了几句什么。I did my best to join in, but the conversation was largely unintelligible.我努力想插上话，可是大部分谈话内容我都听不懂。
英英词典释义
Adjective
1. poorly articulated or enunciated, or drowned by noise;