reform
This word carries a strong sense of structural correction. It suggests that the existing system is not just outdated, but fundamentally broken or unjust, requiring a deliberate overhaul to restore functionality or morality. It is most frequently used in political, legal, and religious contexts where authority is exercised to change the status quo.
While change can be random or superficial, reform is intentional and corrective. It implies a transition from a state of corruption or inefficiency to a state of order and righteousness. In a personal context, it often describes a dramatic moral turnaround, usually following a period of wrongdoing or social failure.
Countable when referring to a specific legislative act or policy change (a reform). Uncountable when referring to the general process of improvement (political reform).