This essay explores the role of the dictionary in religious history, specifically as a conduit of social and intellectual authority brought to bear in religious interpretation, sitting both upstream and downstream of the broader flow of history, culture, and forms of knowledge. Of particular interest is the history of three categories of reference works: the bilingual dictionary (or lexicon) focused on ancient biblical languages; the Bible dictionary, focused on biblical realia, geography, and similar topics; and the theological dictionary, focused on significant biblical ideas associated with particular words or the ancient speakers. The categories are situated historically in the development of biblical scholarship and philology in the West, from the pre-modern era through the contemporary and digital context. Two case studies demonstrate the intersection between dictionaries, biblical interpretation, and cultural ideologies: use of Bible dictionaries and lexicons in the antebellum period as a tool for attacking or defending slavery on biblical grounds in the American South; and the influence on theological dictionaries in the early twentieth century from the anti-Semitic context of Nazi Germany.