In this paper, it is argued that there are relevant similarities between Aristotle’s account of definition and Carnap’s account of explication. To show this, first, Aristotle’s conditions of adequacy for definitions are provided and an outline of the main critique put forward against Aristotle’s account of definition is given. Subsequently, Carnap’s conditions of adequacy for explications are presented and discussed. It is shown that Aristotle’s conditions of extensional correctness can be interpreted against the backdrop of Carnap’s condition of similarity once one skips Aristotelian essentialism and takes a Carnapian and more pragmatic stance. Finally, it is argued that, in general, a complementary rational reconstruction of both approaches allows for resolving problems of interpretational underdetermination.