The Spanish word 'vertebral' comes from the Spanish noun 'vértebra' (vertebra) combined with the suffix '-al' meaning 'relating to'. The word 'vértebra' itself comes from Latin 'vertebra', which was formed from the Latin verb 'vertere' meaning 'to turn' and the instrumental suffix '-bra'. This etymology makes sense because vertebrae are the bones that allow the spine to turn and bend. The suffix '-al' was added to create an adjective meaning 'relating to the vertebrae'.

Some related Spanish words that share the Latin root 'vertere' (to turn) include: 'verter' (to pour, spill), 'vertiente' (slope, watershed), and 'verso' (verse, as in poetry - originally referring to the 'turning' of the line). These words all carry some notion of turning or changing direction in their meanings.

English speakers might recognize the connection to words like 'vertebra' and 'vertebrate'. Other English words from the same Latin root 'vertere' include 'verse', 'version', 'convert', 'divert', 'invert', and 'revert' - all of which involve some kind of turning or changing. The word 'versatile' also comes from this root, originally meaning 'capable of turning' and now meaning 'adaptable'.