"Settled upon" means to make a decision or choice. The antonyms for "settled upon" would be words that convey indecisiveness, uncertainty or hesitation. Some of the antonyms for "settled upon" include: wavered, hesitated, vacillated, dithered, oscillated, waffled, and fluctuated. These words indicate a state of mind where a person is unsure about their decision, or feels conflicted about their choice. For instance, if you wavered on a decision, you were unsure about what to do, and considered different options. Similarly, if you hesitated, you paused momentarily before making a choice, indicating uncertainty.