<p>Talk of ‘defeasible/nondefeasible reasoning’ by some of our leading epistemologists and logicians is misleading. It embodies conceptual confusion about epistemic defeasibility, fallibility, and monotonicity in influential accounts of inferential justification. As argued here, this form of deeply entrenched confusion has blurred the distinction between the concepts of fallibility and defeasibility under the guise of the seemingly benign synonymy between the labels ‘defeasible reasoning’ and ‘nonmonotonic reasoning.’ The careless employment of these labels has had a harmful effect on our understanding of inferential justification. Specifically, it has blurred the fundamental distinction between truth-preservation and justification-preservation in the relevant literature, thus harming the epistemology of reasoning at its core. We have been warned by Timothy Williamson against this kind of confusion, but the warning has gone unheeded. That warning is explained and amplified here on the basis of abundant textual evidence and the discussion of exemplary cases.</p>