The Spanish verb 'andar' (to walk) comes from the Vulgar Latin '*amlare', which itself was derived from Classical Latin 'ambulare' meaning 'to walk'. The Classical Latin term was formed using the prefix 'amb-' meaning 'around, both', suggesting the original concept was related to moving around or in different directions. Over time, the word was simplified from 'ambulare' to '*amlare' in Vulgar Latin, and finally to 'andar' in Spanish, while maintaining its basic meaning of walking or moving on foot.

Some common Spanish words related to 'andar' include 'andador' (walker), 'andante' (walking, moving), and 'andanza' (happening, adventure). These words all share the base meaning of movement or walking, with 'andanza' having evolved to refer to events or experiences that happen while going about.

English speakers might recognize the connection to words like 'amble' and 'ambulance', which come from the same Latin root 'ambulare'. An 'amble' is a relaxed, easy walking pace, while an 'ambulance' was originally a mobile hospital that would 'walk' to where it was needed (though now it refers to the emergency vehicle itself). The word 'perambulate' (to walk around) also contains this same Latin root.