The core of the word, 'whirr', is an imitative or echoic formation, created to mimic the sound of rapid, vibrating, or whizzing motion, such as that made by a bird's wings, a spinning wheel, or a machine. This places it in a category of English words like 'whiz', 'whir', and 'whirr' that all attempt to phonetically represent a specific type of continuous sound. The addition of the '-ing' suffix, a common Germanic participial ending, transforms the base sound into a descriptive adjective for something producing that sound or a noun denoting the sound itself. Thus, 'whirring' elegantly captures the auditory essence of mechanical or rapid motion through its phonetic shape and grammatical form.

The word 'whirring' is a modern English formation derived from the verb 'whirr', which is considered a simplex word of onomatopoeic origin. The suffix '-ing' is a productive English suffix used to form present participles (adjectives) and verbal nouns (gerunds).