The word "gibbering" refers to speaking in a rapid and unintelligible manner, often due to fear, excitement, or madness. There are several synonyms for this word that can be used to convey a similar meaning. Some of these synonyms include babbling, rambling, chattering, prattling, and jabbering. Each of these words can be used to describe someone who is speaking in an incoherent or nonsensical way. Other synonyms for "more gibbering" include blabbering, mumbling, and muttering, which are commonly used to describe individuals who speak in a low, indistinct voice. Regardless of the specific synonym used, they all convey the sense of incomprehensible speech and instability.