vertebra
ver.te.bra \'v*rt-*-br*\ \-(.)bre-, -.bra-\ n or ver.te.brae or vertebras [L, joint, vertebra, fr. vertere to turn - more at WORTH] pl : one of the bony or cartilaginous segments composing the spinal column, c onsisting in some lower vertebrates of several distinct elements which never become united, and in higher vertebrates having a short more or less cylindrical body whose ends articulate by pads of elastic or cartilaginous tissue with those of adjacent vertebrae and a bony arch that encloses the spinal cord
Webster's English Dictionary