You may be most familiar with this term in a medical context: The lower third of the human sternum is called the xiphoid process, which is vaguely sword-shaped and can often be seen and felt in newborns. It typically fuses to the rest of the sternum between ages 15 and 30, but it doesn’t ossify (harden) until around age 40. The word “xiphoid” hails from the Greek “xiphos,” meaning “sword.” The earliest known weapons to be described as swords were found in Turkey and can be traced back to 3300 BCE.