The phrase "most speedball" refers to something that is characterized by high speed and energy. Antonyms for this phrase might include things that are slow-paced, relaxed, or calm. For example, some antonyms for "most speedball" might include "slow-moving," "sedate," "leisurely," "laid-back," or "chilled-out." These terms suggest a more relaxed atmosphere, one that is more conducive to calm and thoughtfulness instead of energetic activity. Depending on the context, antonyms for "most speedball" could be useful for describing anything from a person's personality to a particular event or environment.