There are several antonyms for the phrase "hadst do with," which means to be related or connected to something. One opposite of this phrase could be "unrelated," meaning there is no connection or association. Another antonym could be "disconnected," which implies a separation or lack of relationship between two things. "Irrelevant" is also an antonym, indicating that something has no relevance or importance to a particular situation or topic. On the other hand, the antonym "connected" would suggest a strong relationship or association between two things. Overall, these antonyms provide a range of options when trying to express the opposite meaning of "hadst do with.