The word 'talus' entered English directly from Latin in the 17th century, retaining its dual anatomical and geological meanings. The Latin term is of uncertain origin, though it may be related to an Iberian or Celtic source. The conceptual link between the ankle bone and a slope likely stems from the visual similarity between the sloping side of the ankle joint and a steep, rocky incline. This shared imagery allowed the single Latin word to evolve naturally into two distinct but metaphorically connected modern English definitions.

The word 'talus' is a simplex loanword from Latin, where it meant both "ankle" and "slope." Its functional role is as a complete lexical unit.