What is learning after all? Being the cornerstone of educational psychology, this question has not lost its appeal since there still is no consensus over it. What makes providing a careful definition of learning important is that such definitions carry important pedagogical implications which might not be equally beneficial. This theoretical paper, therefore, has tried to define learning by a novel interdisciplinary approach through connecting educational psychology to philosophy. It has started with the dilemma of a lack of consensus over the definition of definition itself and the necessity for holding a theory of definition. Consequently, Aristotle’s definition theory has been chosen. To be impartial, it has been contrasted with that adopted by Karl Popper- Aristotle’s major critic. Then, mainstream leaning definitions have been investigated. Their inadequacy has been attributed to their non-adherence to a tenable definition theory. The paper recommends a framework for learning definition studies established by adopting Aristotle’s definition theory and other points discussed. Such a framework constitutes guidelines for future studies. These guidelines give future definition studies direction and coherence and allow us to move away from idiosyncrasies reflecting personal bias and, as such, they can direct us towards developing a consensual definition.