mumbledпричастие прошедшего времени Used as an adjective derived from the past participle of the verb 'mumble'.
He gave a mumbled response to the question.
Он дал бормочущий ответ на вопрос.
mumbleпричастие прошедшего времени Used chiefly before nouns to describe speech produced in a low, indistinct manner (e.g., "a mumbled reply").