breastbone

noun

Etymology: From Middle English brust-bon, brestbon, from Old English brēostbān (“breastbone”), equivalent to breast + bone.

1. The central narrow bone in the front of the chest, connecting the collarbone and the top ribs.

   “He lapped out of his hand, then sat up in the sunlight, crossing his shins in front of him, and after a time let his woolly head fall on his breastbone.”