The trochlear nerve is a crucial part of the human nervous system responsible for helping to control eye movement. In medical terminology, it is known as the fourth cranial nerve. There are several synonyms that are commonly used to refer to the trochlear nerve including the superior oblique nerve, which is the muscle that the trochlear nerve innervates. Other synonyms include the fourth nerve, the patellar nerve, and the trochlear cranial nerve. Each of these terms can be used interchangeably when discussing the anatomy and function of the trochlear nerve. Understanding these synonyms can help healthcare professionals better communicate and understand each other when discussing the complexities of the human body.