The term 'tow-headed' derives from the visual similarity between very light, almost whitish-blond hair and the color of 'tow', the coarse and pale fibers of flax or hemp prepared for spinning. The word 'tow' itself has Germanic roots, related to the process of making thread. By the 19th century, this comparison was cemented in American English to describe someone, typically a child, with hair the color of these unbleached fibers. Thus, the compound elegantly links the concrete image of raw, pale flax to a specific human physical trait.

This is a compound adjective formed from the English word 'tow' and the adjective-forming suffix '-headed'. 'Tow' originates from Old English 'tōw' (spinning, thread), related to the process of preparing flax fibers. '-Headed' is a native English suffix from 'head', used to form adjectives describing a characteristic of the head or hair.