ridge bone
/ˈrɪdʒbəʊn/noun
The spine or backbone (now rare ); (in early use also) †a vertebra ( obsolete ). In later use also: any of various other ridge-like bones or projecting parts of bones, such as the keel of the sternum, the spine of the scapula, or the alveolar process of a jawbone.
Origin
Old English; earliest use found in The Lambeth Psalter. Cognate with or formed similarly to Old Frisian hreggben, Middle Dutch ruggebeen, rugghebeen, rugghenbeen, rigghebeen (Dutch ruggebeen), Middle Low German rüggebēn, rüggebein, Old High German ruggibein, ruggibeini, hruggibeini (Middle High German ruggebēn, rückebein, ruckenbein, German Rückenbein), Norwegian ryggbein, Swedish ryggben, Danish rygben from the Germanic base of ridge + the Germanic base of bone.