The antonyms for the phrase "hadst a prospect of" can vary depending on the context in which it is used. If the phrase refers to having hope or a positive outlook, then the antonyms could include despair, hopelessness, doubt, or pessimism. On the other hand, if the phrase refers to having a clear view or understanding, then the antonyms could include confusion, uncertainty, vagueness, or ambiguity. It's important to consider the specific connotation and usage of the phrase in order to identify the most appropriate antonyms. In any case, when we use antonyms, we are highlighting the opposite meaning and creating a contrast for emphasis or clarity in communication.