Cognitive defusion is among the main components of Acceptance and Commitment Therapy (ACT), a contextual behavioral approach to psychotherapy. Defusion serves as a middle-level term, and, as such, may be useful for applying and disseminating behavior science, despite its lower precision. However, some authors argue that for middle-level terms in psychotherapy to be useful to clinicians, they need to be clearly linked to basic behavioral concepts, with higher precision; and that this is not currently the case with defusion. Our objective is to increase the pragmatic utility of the concept of “cognitive defusion” by providing a more nuanced, multi-faceted and process-based definition of the term. In order to do this, we surveyed the ACT literature regarding defusion and critically examined it through the lens of conceptual analysis. This culminated in a revised and updated conceptualization of defusion in terms of its relationship to basic behavioral concepts, in which defusion is an outcome that may be achieved through different processes.