The word 'splatter' is a classic example of onomatopoeia, emerging in the English language in the late 18th century to vividly mimic a specific sound. It is an intensive variant of the earlier verb 'splat,' itself an imitative creation, with the addition of the '-er' suffix frequently used in English to form frequentative or expressive verbs (like clatter, sputter). The logic of its formation is purely sonic, designed to evoke the sharp, wet, and messy impact of a liquid hitting a surface. Its meaning evolved directly from this auditory imitation to describe both the sound itself and the resulting visual effect of scattered droplets.

This is an expressive formation (onomatopoeia) in English, not productively built from classical morphemes. Its role is to phonetically imitate the sound and action it describes.