The Spanish word 'estupendo' meaning 'wonderful' or 'amazing' comes from the Latin word 'stupendus', meaning 'stunning' or 'amazing'. This Latin word was derived from the verb 'stupere', which meant 'to be stunned'. The evolution from Latin to Spanish involved adding the initial 'e-' (a common Spanish development from Latin words beginning with 's' followed by a consonant) while maintaining the core meaning of something so impressive it leaves one stunned or amazed.

Some related Spanish words include 'estupor' (stupor) and 'estúpido' (stupid), which come from the same Latin root 'stupere'. While 'estupendo' developed a positive connotation of something amazingly good, these related words maintained the sense of being mentally stunned or dulled.

English speakers might recognize the connection to words like 'stupendous', 'stupid', and 'stupor', all of which come from the same Latin root 'stupere'. 'Stupendous', like Spanish 'estupendo', developed a positive meaning of 'amazingly impressive', while 'stupid' and 'stupor' retained the notion of mental dullness or being stunned. The parallel between 'stupendous' and 'estupendo' is particularly clear, as they're essentially cognates with the same meaning.