The phrase "dost over" could mean different things in different contexts. However, if we look at it as a combination of two words, "dost" and "over," we can derive some possible meanings and their antonyms. "Dost" is an archaic word meaning "do." Its antonym would be "not do" or "refrain from doing." On the other hand, "over" usually refers to something that is finished or ended. Its antonyms could be "ongoing," "unfinished," or "continuing." So, depending on the intended meaning of "dost over," its antonyms could be "not do ongoing," "refrain from continuing," "do unfinished," or "do ongoing.