1. The smallest and lowest division of the human sternum that is cartilaginous early in life but becomes more or less ossified during adulthood—called also ensiform cartilage, ensiform process. (merriam-webster.com)
2. The cartilaginous section at the lower end of the sternum, which is not attached to any ribs, and gradually ossifies during adult life. (Google Dictionary)
3. The third and lowest segment of the human sternum. (merriam-webster.com)
Syn: xiphisternum, metasternum