As vernacular writers of late medieval England navigated the difficulties of composing orthodox texts, both religious and otherwise, they encountered a limited lexicon. As a consequence, English works of this era are innovative and creative in their use of vocabulary. The Language of Heresy in Late Medieval English Literature examines the way in which these writers complemented seemingly straightforward terms, like heretic, with a range of synonyms that complicated the definitions of both those words and orthodoxy itself. This text proposes four specific terms that become synonymous with heretic in the parlance of medieval English writers of the 14th and 15th centuries: jangler, Jew, Saracen, and witch. These four labels are especially important insofar as they represent the way in which medieval Christianity appropriated and subverted the marginalized identities of women, illiterate laity, Jews, and Muslims to promote an image of unity despite constantly-shifting reality.