Wiktionary
n. (context anatomy English) Any of the five vertebrae in the loin or lower back region of the spine.
WordNet
n. one of 5 vertebrae in the human vertebral column; lumbar vertebrae extend from the twelfth thoracic vertebra down to the sacral vertebrae
Usage examples of "lumbar vertebra".
It appeared as if she'd had an extensive laminectomy involving the fourth lumbar vertebra.
It ends at about the first or second lumbar vertebra, just in the small of the back.
But many of the vertebrae had been cut open in the same way, from the first lumbar vertebra all the way to the sacrum.
I didn't get a real good look, but what Eddie had in his right hand, nestled up against the other man's fourth lumbar vertebra, looked an awful lot like a Charter Arms .
Felt a sharp prick through my coat abeam the first lumbar vertebra.