The word 'sputtering' originates from the verb 'sputter', which first appeared in English in the late 16th century. It is an onomatopoeic formation, imitating the sound of repeated, moist, explosive noises, such as spitting or fat frying in a pan. This core idea of making rapid, intermittent spitting sounds was extended metaphorically to describe similar noises from malfunctioning engines or electrical equipment. The addition of the '-ing' suffix forms either the present participle adjective, describing something that makes such sounds, or a gerund noun denoting the action or process itself.

Structure: sputter + ing - sputter: A word of imitative origin, likely from the base of 'sput' (to spit) combined with a frequentative suffix '-er', mimicking the sound of repeated spitting or spattering. - ing: A suffix from Old English '-ende', '-inge', used to form the present participle of verbs or nouns denoting action or material.