What term refers to the act of changing from one use or function to another?

The term "conversion" refers specifically to the act of changing something from one use or function to another. This concept can be applied in various contexts, such as the conversion of energy from one form to another (like converting sunlight into electricity via solar panels) or in a broader sense, like converting a building from residential to commercial use.

This word emphasizes the process of transformation that retains some aspects of the original form while adopting a new purpose, making it the most appropriate choice for the question. The other terms have distinct meanings that do not align with the concept of changing from one use to another. For instance, distillation refers to the process of separating components from a liquid mixture based on differences in their boiling points, eradication signifies the complete removal or destruction of something, and enervation means weakening or loss of energy or vitality, none of which convey the idea of functional change.