unintelligible
adjectiveUK /ˌʌnɪnˈtelɪdʒəbl/
US /ˌʌnɪnˈtelɪdʒəbl/
Too hard to understand.
The old radio made the announcer's voice sound unintelligible.
OTHER MEANINGS
2. Not able to be understood by the mind; beyond comprehension.
The professor's lecture on quantum gravity was unintelligible to most of the audience.
3. Spoken or written so poorly that the meaning cannot be worked out.
His handwriting was so unintelligible that even he could not read it later.
4. In linguistics, describing speech sounds that cannot be identified as meaningful words.
The recording was too noisy, leaving only unintelligible sounds.