Antonyms for the phrase "hadst a swing at" could vary depending on the context in which it is used. However, some possible antonyms may include "abstained," "refrained," "avoided," "evaded," "neglected," "overlooked," and "forgo." These words suggest a lack of action or involvement in a particular situation or event. They imply a conscious decision not to engage in a particular activity or behavior. Therefore, if someone says they had abstained from having a swing at something, they are expressing their choice not to engage in that particular activity or behavior.