The word "determining" refers to settling or deciding something. Its antonyms include the words "undeterminable," "indecisive," "unclear," and "ambiguous." "Undeterminable" means something that cannot be settled or decided. The term "indecisive" refers to being unable to make up one's mind, while "unclear" conveys a lack of clarity or certainty in a situation. Finally, "ambiguous" means something that is open to more than one interpretation and can thus not be decided with any degree of certainty. These antonyms highlight the different shades of meaning that exist within the concept of determining something with certainty.