Phren

Phren (Ancient Greek: φρήν phrēn "mind", genitive: φρενός) is an Ancient Greek word for brain or mind. It's latinised form is "fren" and is found in the English language words schizophrenia, phrenitis, phrenic nerve, frenzy, frenetic. Some ancient Greeks, including Aristotle, believed that the "mind" was located in the heart rather than the cranium. This explains the second meaning of "φρήν": thoracic diaphragm (hence the name of the "phrenic nerve").