The phrase "hadst knowledge of" implies that someone has knowledge or awareness of something. The antonyms for the term can be "ignorance," "unfamiliar," "inexperienced," and "naivety." If someone lacks knowledge in a particular area, they are considered ignorant. When you're unfamiliar with a subject, you have no knowledge of it. Inexperienced means someone who has not gained practice or expertise in a specific field. Naivety refers to a person's lack of life experience, knowledge, or wisdom. Therefore, if someone says they hadst no knowledge of a topic, it means they lacked information, were inexperienced, or ignorant.