gibbering

The host, who was 18 when she joined the BBC kids' TV show, said she was "pushed to the limit" by behaviour that left her a "shaking, gibbering wreck."

"You're lucky he's not been reduced to a gibbering imbecile."

“He sits there in senile dementia,” the governor said, “with gangrene heart and rotting brain, grimacing at every reform, chattering impotently at all things that are decent, frothing, fuming, violently gibbering, going down to his grave in snarling infamy.”

Henry—imagining, perhaps, some trembling Kassandra gibbering prophecies to a chorus of policemen—was far more concerned about the psychic.

While I was a gibbering mess, Ellen was stunned into a weird, calm silence.