nounpl. -·brae· or -·bras
Origin of vertebraL, a joint, vertebra from vertere, to turn: see verse
nounpl. ver·te·brae, or ver·te·bras
Origin of vertebraMiddle English from Latin from vertere to turn ; see wer-2 in Indo-European roots.
From Latin vertebra (“joint"), from vertere (“to turn"). Having multiple vertebrae (plural of vertebra) in one's backbone instead of having a single bone or solid spine, allows for the movement of the body with bends and turns. Hence meaning 1.