1. A topic or matter that is not widely known, difficult to understand, or unclear in nature
Medieval Byzantine theology is an obscure subject that few scholars study.
A teologia bizantina medieval é um assunto obscuro que poucos estudiosos pesquisam.
2. A subject that lacks clarity or is deliberately vague and hard to comprehend
The lecturer spoke about such an obscure subject that most students couldn't follow.
O palestrante falou sobre um assunto tão obscuro que a maioria dos alunos não conseguiu acompanhar.