I mumbled some unintelligible half-apology and took the elevator down to the lobby.
His sleep was restless, and every so often he mumbled a few unintelligible words.
The idea of a cipher system is to disguise confidential information in such a way that its meaning is unintelligible to an unauthorized person.
He began to speak in a tongue which was unintelligible to Carl yet which he thought he could almost understand.
Well, there's ironically post-modern and then there's almost unintelligible .
When understood, these attractors often explain complex, seemingly unintelligible behaviour.
I may leave parties a little earlier than usual, when the chat gets unintelligible to anyone who isn't hammered.
For most people, indeed, the acts of a sex murderer are impossible and unintelligible .
I mumbled something deliberately unintelligible and hopped down.
Everything else it says is as unintelligible as the warbling of a canary.