The term “bilious” in literature has been used in remarkably varied ways, often to evoke a sense of malaise, irritability, or a generally unhealthy appearance. In many works, it signifies a person’s irritable or bitter state—such as the cantankerous mood depicted in Dostoyevsky’s portrayal of a wakeful, hateful disposition [1] or the distinctly bitter look described in Thackeray’s character [2]. At times, “bilious” extends beyond mood to describe physical appearance, as when Irving characterizes someone with a lean, unhealthy look [3] or when Whitman notes a countenance painted a sickly yellow [4, 5]. In other contexts, the term takes on a more literal, medical meaning, relating to bodily ailments as seen in texts by T. H. Pardo de Tavera [6, 7, 8, 9] and Napoleon [10]. Even Joyce uses it metaphorically when a clock’s stare seems imbued with malice [11]. Across these examples, “bilious” serves as a flexible descriptor, enhancing character depictions by linking physical decline, disordered temperament, and even objects to an overarching theme of unhealthiness or bitterness.