The definition of unintelligible is cannot be understood.
An example of something unintelligible is a voice mail message left on a cell phone with a bad connection.
not intelligible; that cannot be understood; incomprehensible
Difficult or impossible to understand or comprehend; incomprehensible: unintelligible remarks; an unintelligible prose passage.
(comparative more unintelligible, superlative most unintelligible)
- not intelligible; unable to be understood
un- +"Ž intelligible