The word 'whiz' is a classic example of onomatopoeia, a linguistic echo of the sound it describes. It emerged in the mid-16th century, directly imitating the sharp, hissing or buzzing noise of an object, such as an arrow or bullet, cutting rapidly through the air. This phonetic imitation provided a vivid and efficient way to name the action and its accompanying sound. Over time, the meaning extended metaphorically from the literal sound of speed to describe any person or action characterized by remarkable quickness and skill, giving us the modern sense of a 'whiz kid' or the act of 'whizzing through' a task.

This word is an onomatopoeic formation, imitating the sound of something moving swiftly through the air. It is not productively built from separable morphemes in modern English.