Lucretius Syllabification: (Lu·cre·tius)Pronunciation: /lo͞oˈkrēSHəs/Definition of Lucretius (circa 94-circa 55 bc), Roman poet and philosopher; full name Titus Lucretius Carus. His didactic epic poem On the Nature of Things is an exposition of the materialist atomist physics of Epicurus. Lucretius in other Oxford dictionaries Definition of Lucretius in the British & World English dictionary