Correct spelling for the English word "vertebrac" is [vˈɜːtɪbɹˌak], [vˈɜːtɪbɹˌak], [v_ˈɜː_t_ɪ_b_ɹ_ˌa_k] (IPA phonetic alphabet).
I'm not certain, but I believe you might be referring to the word vertebra. The word vertebra comes from the Latin term vertebra, which means a joint or a joint of the spinal column. It is derived from the earlier Latin word vertere, which means to turn. This is because the vertebral column is comprised of individual bones that are connected by joints and allow movement, supporting the idea of turning or twisting.