Which word describes something that is likely to be false but might seem plausible?

The word that describes something likely to be false but might seem plausible is "spurious." This term refers to things that are not what they appear to be; they may present themselves as valid or genuine but are actually deceptive or false in nature. An example of spurious information could be a misleading statistic or a fake news story that, while it might seem credible at first glance, lacks a solid foundation or truth.

In contrast, the other choices represent different nuances. "Credible" refers to something that is believable or trustworthy. "Factitious" pertains to something artificially created or manufactured, often suggesting a lack of authenticity, but not necessarily implying falsehood. "Delusional" relates to a belief that is persistently held despite evidence to the contrary, typically in a mental health context, which does not align with the idea of something seeming plausible while being likely false. Thus, "spurious" is the most accurate word for describing this concept.