The Spanish word 'baboso' comes from combining two elements: the noun 'baba' (meaning 'drool' or 'saliva') and the suffix '-oso' (meaning 'full of' or 'having the quality of'). The noun 'baba' itself comes from Latin '*baba', which had the same meaning of 'drool' or 'saliva'. When these elements combined, they created 'baboso', which literally means 'full of drool' or 'drooling', and by extension came to also mean 'foolish' or 'silly' - likely drawing a connection between drooling and foolishness.

The simpler Spanish word 'baba' is directly related to 'baboso', as it's the root word from which 'baboso' is formed. While 'baba' simply means 'drool' or 'saliva', adding the suffix '-oso' transforms it into an adjective describing someone or something characterized by drooling. This pattern of adding '-oso' to create adjectives is common in Spanish, similar to how English uses '-y' (like in 'slimy' or 'messy').

While there aren't any common English words directly related to 'baboso', the concept of using words related to 'drooling' to indicate foolishness is also present in English expressions like 'drooling idiot' or 'slobbering fool'. The Spanish suffix '-oso' is actually cognate with the English '-ous' (as in 'dangerous' or 'numerous'), as both come from Latin '-osus', though this might be less obvious to learners.