Cortical rhythm refers to the electrical patterns that are generated by the brain's cortex. As a complex phenomenon, it has earned a wide array of synonyms that serves to describe the patterns with equal accuracy and detail. One of the major synonyms of cortical rhythm is Electroencephalogram (EEG) which measures electrical activity in the brain. Other synonyms include brainwave, neural oscillation, cognitive rhythm and oscillatory activity. Each of them describes the same process of rhythmic activity in the brain and offers different insights into the complex workings of the cortex. These synonyms are particularly important for the field of neuroscience where they facilitate communication between researchers and their audiences.