People often appear to conflate anger and disgust, seemingly using expressions of both emotions interchangeably in response to moral violations. Yet, anger and moral disgust differ in their antecedents and consequences. These empirical observations are associated with two broad theoretical perspectives: one describes expressions of moral disgust as metaphors for anger, whereas the other describes moral disgust as functionally distinct from anger. Both accounts have received empirical support from separate and seemingly inconsistent literatures. The present study seeks to resolve this inconsistency by focusing on the different ways moral emotions have been measured. We formalise three theoretical models of moral emotions: one in which expressions of disgust are purely associated with anger (but not physiological disgust), one in which disgust and anger are fully separated and have distinct functions, and an integrative model that accommodates both metaphorical use in language and distinctive function. We test these models on responses to moral violations (four studies; N = 1608). Our results suggest that moral disgust has distinct functions, but that expressions of moral disgust are sometimes used to convey moralistic anger. These findings have implications for the theoretical status and measurement of moral emotions.