'balbutiate' originates from Latin (or Late Latin), specifically the verb 'balbutire', where the root 'balbut-' was imitative of faltering speech (a stammering sound).

'balbutire' passed into French as 'balbutier' and was later adopted into English as 'balbutiate' (verb), with the adjective form 'balbutient' derived from that verb in later English usage.

Initially it meant 'to stammer' (an onomatopoeic description of halting speech), and this basic sense has been retained into modern usage as 'to speak haltingly' or 'stammering'.