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1. verb - to grumble and mutter simultaneously.

2. verb - to incomprehensibly express displeasure vocally.

"Dang kids and their stupid cell phones", the unhappy codger gruttered.

The vocal expression which is gruttered is called a "grutterance".
by G-Force March 22, 2006

Words related to grutter

complain grumble grutterance mutter utterance