Propertius, SextusPronunciation: /prəˈpəːʃəs/Definition of Propertius, Sextus (circa 50-circa 16 bc), Roman poet. His four books of elegies are largely concerned with his love affair with a woman whom he called Cynthia. Propertius, Sextus in other Oxford dictionaries Definition of Propertius, Sextus in the US English dictionary