The Spanish word 'plebe' comes from the Latin word 'plebs', which meant 'common people'. This Latin term is related to the Ancient Greek word 'plethos' (πλῆθος), meaning 'multitude' or 'mass'. The word maintained its meaning referring to common people or the masses as it evolved from Latin into Spanish, with only minor changes to its form.

A related Spanish word is 'plebeyo' (meaning 'plebeian' or 'common'), which comes from the same Latin root. Another related term is 'plebiscito' (meaning 'plebiscite' or 'referendum'), which literally meant a decree or law made by the common people in ancient Rome.

English speakers might recognize this word's connection to 'plebeian', which also comes from Latin 'plebs' and refers to common people or those of lower social status. The word 'plebiscite' (a direct vote by all qualified voters) is another English cognate that shares this etymology.