The word 'wisp' first appeared in Middle English, its origins shrouded in some mystery but with plausible connections to Old Norse. It may be related to the Old Norse word 'visk,' meaning a wisp or a bundle of straw, used for wiping or brushing. Another possibility is an imitative origin, mimicking the sound or swift, light motion of something being whisked away. From its early concrete meanings denoting a small bundle of straw or twigs used as a torch or for cleaning, the term evolved through semantic broadening. This evolution followed a clear logic of association: from a small, bundled physical object, it extended metaphorically to any small, thin, and often fleeting strand or fragment, such as a wisp of hair, cloud, or smoke, capturing its delicate and insubstantial nature.

The word 'wisp' is a simplex word of uncertain origin, likely from a Scandinavian source or imitative of a whisking or brushing motion. It functions as a single, unanalyzable morpheme in modern English.