The tentorial angle refers to the angle formed between the cerebrum and cerebellum in the brain. However, we can discuss antonyms for the word tentorial angle, which are unrelated to the meaning of the term. Some possible antonyms for tentorial angle include, but are not limited to: flat, level, perpendicular, horizontal, sloping, parallel, straight, upright, even, and smooth. These opposite terms have completely different meanings and are not related to the anatomy of the brain. It's important to understand the difference between synonyms, antonyms, and homonyms to ensure clear communication and avoid confusion in language.