Definition
To do something 'terminally' means to do it in a way that signifies an end or a final stage, especially in the context of a disease or condition that cannot be cured. It suggests a situation that is irreversible and will ultimately lead to death. This can also be used figuratively to describe something that is hopelessly broken or beyond repair. Think of it as the 'point of no return'. It implies a sense of finality and inevitability. It's more than just 'badly', it's permanently bad.