What word describes a person who tends to doubt or question accepted beliefs?

The term that accurately describes a person who tends to doubt or question accepted beliefs is "skeptical." A skeptical individual approaches information, claims, or beliefs with a mindset that demands evidence and rational support before accepting them as true. This mindset is crucial in areas like science and philosophy, where critical thinking and questioning established norms can lead to new insights and understandings.

In contrast, the other terms do not align with this definition. "Solvent" refers to a substance, typically a liquid, capable of dissolving other substances. "Squander" means to waste something, typically time or resources, in a reckless or foolish manner. "Sanctimonious" describes a person who makes a show of being morally superior to others, often hypocritically. None of these alternatives encapsulate the essence of doubt or questioning regarding accepted beliefs.