The word "ingrate" has long served as a sharp, resonant label in literature, used to condemn those who repudiate kindness or betray trust. In the classic fables of La Fontaine ([1], [2], [3], [4]), the term is deployed with biting irony to underscore moral failings, while Milton both in Paradise Lost ([5], [6]) and other works employs it to articulate defiance against those who arrogantly place themselves above their peers. Authors like Dumas ([7], [8]) and Dickens ([9], [10]) use "ingrate" as a direct, emotionally charged epithet that heightens the personal conflict, and even in more poetic contexts—such as in the works of Sappho ([11]) and Burns ([12])—the word conveys a potent mix of betrayal and sorrow. Its presence also spans broader discourse in philosophical and political texts, from Lucretius’s rigorous moral inquiries ([13]) to Jefferson's critical address in the Declaration ([14]), while modern narratives, like Kornbluth's ([15]), reveal its enduring versatility. This diverse application illustrates how "ingrate" consistently functions as a powerful indictment of ungratefulness throughout literary history.