ῥάχις

Etymology
According to Beekes of origin or related to 🇨🇬. Compare.

Noun

 * 1) chine, lower part of the back
 * 2)  spine or backbone
 * 3) anything ridged like a backbone:
 * 4) ridge of a hill or mountain
 * 5) bridge of the nose
 * 6)  midrib of a leaf
 * 7) sharp projection on the middle of the shoulder blade
 * 8) outer edge of the arm of the polypus