Which of the following words means "dirty" and does NOT denote a mental state?

The word "sordidus" is the correct choice as it directly translates to "dirty" in a physical sense, often referring to things that are unclean or filthy. This term pertains to a tangible state of being rather than an emotion or mental condition.

In contrast, "īrātus" translates to "angry," which clearly describes a mental state, while "incertus" means "uncertain," which also relates to a mental condition. The term "territus," meaning "frightened," pertains to an emotional or psychological state. Therefore, "sordidus," being purely descriptive of physical dirtiness, stands out as the only option that does not denote a mental state.