The Spanish word 'decoro' (meaning 'decorum, honor') comes from the Latin word 'decorum', which meant 'that which is seemly or proper.' The Latin 'decorum' itself derived from 'decus', meaning 'ornament' or 'dignity.' This evolution shows how the concept moved from physical ornamentation to a more abstract sense of proper behavior and dignity.

The Spanish word 'decorar' (to decorate) and 'decoración' (decoration) are related words that maintained a connection to the original Latin meaning of physical ornamentation, while 'decoro' evolved to represent moral and behavioral propriety.

English speakers might recognize the connection to the word 'decorum', which has essentially the same meaning as Spanish 'decoro'. Both come from the same Latin root. The English words 'decent' and 'decoration' are also related, showing how the concept branched into both proper behavior ('decent') and physical ornamentation ('decoration').