People vary in the precision with which they report on their emotions, known as emotional granularity, and this precision predicts their ability to regulate their emotions. It is not yet known, however, whether links between emotion regulation and emotional granularity are due to variation knowledge of emotion words -- specifically, individuals’ reported usage, understanding, and ability to accurately define emotion words. In the present report, we combined data from six studies to address this gap in the literature using an integrative data analysis. Participants across the studies reported on their usage and understanding of a list of highly-granular emotion words, and were tested for their accuracy of definition. They also completed questionnaire measures of emotional granularity and emotion dysregulation. Emotion word accuracy and understanding were highly correlated, so individual models tested each separately to predict emotion regulation difficulty. In the model including usage and understanding, we observed a main effect of understanding, such that participants with greater self-assessed understanding of emotion words reported less difficulty regulating their emotions. Similar effects were found for the model including usage and accuracy, such that individuals with higher emotion word accuracy had less difficulty regulating their emotions. Critically, these findings held when accounting for self-reported granularity, suggesting the value of emotion word knowledge measures for predicting dysregulated emotions. Future work should examine how individuals’ emotion word knowledge is also linked to mental health outcomes.