The Spanish verb 'caminar' (to walk) has its roots in the Celtic word 'cam', meaning 'step'. This Celtic root evolved into the Vulgar Latin word 'camminus', meaning 'path' or 'way'. In Spanish, this became 'camino' (meaning path or way), and with the addition of the verbal suffix '-ar', it formed 'caminar', meaning 'to walk' or literally 'to take a path'.

This etymology shows how the meaning evolved from a basic concept of a 'step' to a 'path', and finally to the action of walking along that path.

The most obvious related Spanish word is 'camino', meaning 'path' or 'way', which is actually the base word from which 'caminar' was formed. This noun is often encountered in phrases like 'el Camino Real' (the Royal Road) or the famous pilgrimage route 'el Camino de Santiago' (the Way of St. James). Another related word is 'caminante', meaning 'walker' or 'wanderer'.

While English doesn't have many direct cognates from this Celtic root, the word 'chemist' and 'chemistry' are actually distant relatives, as they come from the Medieval Latin 'caminus' meaning 'road' or 'path', which was used metaphorically to refer to the process or path of chemical operations. However, this connection is quite remote and might not be particularly helpful for Spanish learners.