Which word conveys the idea of being unwavering or unaffected by change?

The word "Constant" perfectly encapsulates the idea of being unwavering or unaffected by change. It refers to something that remains unchanged, stable, and steadfast over time, regardless of external circumstances. This term is often used in various contexts, such as mathematics, where a constant value does not fluctuate, or in personal traits, where someone described as constant maintains their principles and behavior consistently.

In contrast, while "Responsive" suggests the ability to react or adapt to changes, it implies a level of fluidity rather than staunch steadfastness. "Stabile" is less commonly used and may not clearly communicate the notion of being unaffected by change in a broad context. "Fixed" does convey a sense of immobility, but it can imply lack of progress or adaptability, which may not be the intended nuance of unwavering resolve. Thus, while other words have their merits, "Constant" is the most accurate choice for expressing the idea of being unwavering or unaffected by change.