In literature, the term implausible often serves to signal that a narrative element, a scientific rationale, or a character’s claim stretches the bounds of believability. It is used to qualify certain plot points or theories as not wholly credible, whether describing an outline that feels "baldly implausible" [1] or critiquing a scientific basis that appears weak [2]. At times, it captures a tension between what seems possible and what feels too stretchingly inventive—such as when a character’s own denial of involvement appears on the surface plausible, yet is undermined by the surrounding narrative [3] or when actions are deemed so unlikely they challenge the narrative’s internal logic [4, 5]. The word can also delineate a fine line between believable reasoning and extravagant conjecture, as when theories or doctrines are weighed against evidence that tilts them toward the unacceptable [6, 7].