Gradually: This implies a slow, steady change.
Slowly: Similar to gradually, this suggests a slow pace.
Smoothly: This implies a seamless and effortless transition.
Gently: This suggests a soft and delicate approach.
Carefully: This implies a cautious and deliberate approach.
Methodically: This suggests a systematic and organized approach.
Gradually: This implies a slow, steady change.
Steadily: This implies a consistent and unwavering progression.
Progressively: This implies a gradual advancement or improvement.
Example:
* Abruptly: "He stopped talking abruptly."
* Gradually: "He stopped talking gradually, his voice fading away."
The best antonym will depend on the specific situation and the desired meaning.