General:
* Ignorant: This is a straightforward and direct term, simply meaning lacking knowledge.
* Uninformed: Similar to ignorant, but suggests a lack of information rather than an inability to learn.
* Uneducated: This implies a lack of formal education or training on the subject.
* Naive: This suggests a lack of experience and understanding of the world, leading to a lack of knowledge.
More negative:
* Pretentious: This implies someone who acts as if they know more than they do, often to impress others.
* Arrogant: This suggests an inflated sense of self-importance and a belief that they are superior in knowledge.
* Boastful: This describes someone who exaggerates their knowledge or experience.
* Blatant: This suggests that someone is clearly and obviously talking about something they don't understand.
Less negative:
* Misinformed: This implies that the person has inaccurate information, rather than no information at all.
* Unfamiliar: This suggests that the person simply doesn't have enough experience or exposure to the topic.
The best adjective to use will depend on the specific context and the tone you want to convey.