Simple past tense and past participle of gibber; to talk incomprehensibly(verb)
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Use "gibbered" in a sentence
"But he nearly screamed when she succumbed to that caress so at the very first of the courtship and mowed and gibbered and squealed little, queer, pig-like gurgly noises of delight."
"He gibbered his own rage and hurt, and, stooping, dealt Jerry a tremendous blow alongside the head and neck."
""It was an ancient Chinese philosopher who is first recorded as having said, what doubtlessly the cave men before him gibbered, namely, that a woman pursues a man by fluttering away in advance of him.""