Wiktionary
antiacceleration
a. 1 Opposing academic acceleration. 2 (context scifi English) Preventing or counteracting acceleration.
Usage examples of "antiacceleration".
The antiacceleration and gravity coils in the ship worked so smoothly I didn't even realize it until I saw the lights in the scenery below slowing down.
We had three times their effective speed since we had antiacceleration devices which they lacked.