Antonyms for the term "Cranial Nerve IV," also known as the Trochlear Nerve, could include terms such as "peripheral nerve," "spinal nerve," or "autonomic nerve," as these all refer to different kinds of nerves within the body. Additionally, antonyms for "Cranial Nerve IV" could include related terms such as "optic nerve," "olfactory nerve," or "vestibulocochlear nerve," which are all other cranial nerves that control various aspects of vision, hearing, and smell. It's important to note that while these terms may be antonyms in a sense, they are all still part of the complex network of nerves that make up the human body and work together to help us function properly.