The word 'tangle' entered Middle English from a Scandinavian source, akin to the Old Norse word for a specific type of seaweed known for its long, intertwining fronds. This literal sense of a twisted, knotted mass of marine vegetation provided a powerful and concrete metaphor. Over time, the meaning broadened beyond the botanical reference to describe any confused interweaving of threads, hair, or lines. Ultimately, this physical sense extended metaphorically to describe complicated, confused, or entangled situations, arguments, or states of mind, completing its journey from a name for seaweed to an abstract noun and verb.

The word 'tangle' is a simplex word of Scandinavian origin, likely from Old Norse 'þǫngull' meaning "seaweed" or "sea-tangle," a type of long, twisting seaweed. The root is not productively divisible into separate morphemes in modern English.