The phrase "hadst a hunch" typically refers to having a strong intuition or suspicion about something. Antonyms for this phrase would include having no idea or clue about a particular situation or feeling unsure or uncertain about something. Other antonyms could include feeling indifferent, disinterested, or unconcerned. In some cases, antonyms for "hadst a hunch" could also include having a false or misguided assumption, or being completely wrong about a particular situation. Regardless of the situation, antonyms for "hadst a hunch" typically involve a lack of confidence or knowledge about something.