In this article, we examine how journalists try to uphold ideals of objectivity, clarity, and epistemic authority when using four overlapping terms: fake news, junk news, misinformation, and disinformation. Drawing on 16 qualitative interviews with journalists in Denmark, our study finds that journalists struggle to convert the ideals of clarity and objectivity into a coherent conceptual practice. Across interviews, journalists disagree on which concepts to use and how to define them, accusing academics of producing too technical definitions, politicians of diluting meaning, and journalistic peers of being insufficiently objective. Drawing on insights from journalism scholarship and rhetorical argumentation theory, we highlight how such disagreements reveal a fundamental tension in journalistic claims to epistemic authority, causing a continuous search for unambiguous terms, which in turn produces the very ambiguity that journalists seek to avoid.