This is the author accepted manuscript. The final version is available from Il Poligrafo via the link in this recordThe question of whether substance is homonymous or synonymous is rarely raised as such in the vast literature on Aristotle’s theory of substance. The present paper aims at filling this gap by tracing Aristotle’s thoughts about how substance is said. It is argued that substance is (problematically) synonymous in the Categories, while homonymy is the right framework for understanding the hylomorphic model of substance that Aristotle presents in the Physics, the De Anima and the Metaphysics. The paper also discusses at some length whether the variety of homonymy that applies to substance on the hylomorphic model should be seen as...