Scaphocephaly, also known as sagittal craniosynostosis, is a congenital condition characterized by the premature fusion of the sagittal suture in an infant's skull. This early fusion restricts the skull's natural growth, causing it to elongate and become narrow, resembling a boat shape. The term "scaphocephaly" is derived from the Greek words "scapho," meaning boat, and "cephaly," meaning head.