ῥάχις
rhachis
- a spine
STEPBible TBESG
Glosses: a spine
1. the lower part of the back, the chine , (Iliad by Homer): then, the spine or backbone , ὑπὸ ῥάχιν παγῆναι to be impaled, (Aeschulus Tragicus)
2. anything ridged like the backbone, a mountain-ridge , (Herdotus Historicus) (ML)