spinal column vs rachis

spinal column and rachis both are nouns.

Word	Noun	Adjective	Verb	Adverb
spinal column	Yes	No	No	No
rachis	Yes	No	No	No

As nouns, spinal column and rachis are synonyms defined as:

spinal column and rachis: the series of vertebrae forming the axis of the skeleton and protecting the spinal cord

Other synonyms of spinal column include back, backbone, spine, vertebral column.

spinal column (noun)	rachis (noun)
the series of vertebrae forming the axis of the skeleton and protecting the spinal cord	the series of vertebrae forming the axis of the skeleton and protecting the spinal cord
	axis of a compound leaf or compound inflorescence