18. Xiphoid // Sword shaped
From the Greek xiphos for sword. If you prefer Latin roots, there’s ensiform (from Latin ensis). The little piece of pointy cartilage at the bottom of your sternum where the lowest ribs meet is called the xiphoid process.
During CPR, the hands should be positioned mid-sternum, well above the xiphoid process.
Do check out the list where this came from: 18 Fancy Words for Specific Shapes by Mental Floss--some great scientific and medical words there.