Masaccio Syllabification: (Ma·sac·cio)Pronunciation: /məˈsäCHē-ō/Definition of Masaccio (1401–28), Italian painter; born Tommaso Giovanni di Simone Guidi. The first artist to apply the laws of perspective to painting, he is known particularly for his frescoes in the Brancacci Chapel in Florence (1424–27). Masaccio in other Oxford dictionaries Definition of Masaccio in the British & World English dictionary