The Spanish word 'caldito' comes from 'caldo' (meaning 'broth') with the addition of the diminutive suffix '-ito', making it mean 'small broth' or 'little broth'. The word 'caldo' itself can be traced back to the Vulgar Latin 'caldus', which was a contracted form of Classical Latin 'calidus', meaning 'hot' or 'warm'. This etymology makes intuitive sense since broths are typically served hot, and the meaning evolved from the temperature of the liquid to refer to the soup or broth itself.

A simpler and more common related Spanish word is 'caldo' (broth), which is the base word from which 'caldito' is formed. Another related word is 'caliente' (hot), which also comes from the same Latin root 'calidus'. These words share the common theme of heat or warmth in their meanings.

While not directly cognate, English speakers might recognize a connection to words like 'calorie' and 'cauldron', which are also derived from the Latin 'calidus'. A calorie was originally a measure of heat, while a cauldron is a large pot used for heating liquids - both connecting back to the same concept of heat that gave us the Spanish 'caldito'.