lumbar vertebra vs vertebra

lumbar vertebra and vertebra both are nouns.

Word	Noun	Adjective	Verb	Adverb
lumbar vertebra	Yes	No	No	No
vertebra	Yes	No	No	No

As nouns, vertebra is a hypernym of lumbar vertebra; that is, vertebra is a word with a broader meaning than lumbar vertebra:

lumbar vertebra: one of 5 vertebrae in the human vertebral column; lumbar vertebrae extend from the twelfth thoracic vertebra down to the sacral vertebrae
vertebra: one of the bony segments of the spinal column

lumbar vertebra (noun)	vertebra (noun)
one of 5 vertebrae in the human vertebral column; lumbar vertebrae extend from the twelfth thoracic vertebra down to the sacral vertebrae	one of the bony segments of the spinal column