Probabilistic means related to probability or likelihood. If you want to use a synonym for this word, you could consider using the term "statistical" instead. This word implies a calculation of likelihood based on measurable data. Other alternatives for probabilistic could include "chance-based", "random", or "uncertain". These words all indicate an element of unknown or unpredictable outcomes. Another option could be "probabilistical", which is a less common variant of the word probabilistic. Whatever synonym you choose, be sure to use the appropriate term based on your intended meaning and context, so that your message is conveyed clearly.