Plutarch Syllabification: (Plu·tarch)Pronunciation: /ˈplo͞oˌtärk/Definition of Plutarch (circa 46-circa 120), Greek biographer and philosopher; Latin name Lucius Mestrius Plutarchus. He is chiefly known for Parallel Lives, a collection of biographies of prominent Greeks and Romans. Plutarch in other Oxford dictionaries Definition of Plutarch in the British & World English dictionary