The Spanish word 'baba', meaning 'drool' or 'saliva', comes directly from the Vulgar Latin word '*baba' with the same meaning. This is considered to be an onomatopoeic or expressive formation, possibly imitating the sound of baby talk or the sound of drooling itself. The word has remained remarkably stable in both form and meaning since Vulgar Latin times.

Some related Spanish words include 'babear' (to drool), 'baboso' (slobbery or drooling), and 'babero' (bib). These are all straightforward derivatives of 'baba' that relate to drooling or protecting against drool.

While English 'baby' might seem related due to the similar sound and the association with drooling babies, it actually has a different etymology. However, English has borrowed the word 'babassu' (a type of palm tree) from Portuguese, where it ultimately derives from a Tupi word that may have been influenced by this same Latin root due to the oily nature of the palm's fruit.