The antonyms for the phrase "setting on" would be "turning off," "stopping," or "discontinuing." These antonyms signify the opposite action of starting or beginning something. For instance, if a person sets on a new project, the opposite action would be to turn off or stop working on it. Similarly, if a person sets on a journey, the opposite would be to discontinue it or stay put. Antonyms for "setting on" can also include "leaving behind" or "abandoning," which suggests moving away from something rather than towards it. In summary, antonyms for "setting on" signify the opposite action of starting or initiating a process.