What is the term for making something better or correcting a fault?

The term "ameliorate" specifically means to make something better or to improve a situation. It is commonly used in contexts where conditions are being enhanced, particularly in social, economic, or environmental issues. The root of the word comes from the Latin "ameliorare," which means to make better.

In contrast, "baleful" refers to something that is harmful or threatening, "diminutive" describes something that is very small or tiny, and "infirmity" denotes a physical weakness or illness. None of these alternatives convey the idea of improvement or correction in the way that "ameliorate" does. Therefore, it is clear that the correct choice focuses on the action of enhancing or rectifying a negative condition or fault.