n. 25B6; noun
an injured backbone : SPINE, spinal column, vertebral column, vertebrae; back; Anatomy dorsum, rachis. See list at vertebra .
infantry are the backbone of most armies : MAINSTAY, cornerstone, foundation, chief support, buttress, pillar.
he has enough backbone to see us through : STRENGTH OF CHARACTER, strength of will, firmness of purpose, firmness, resolution, resolve, grit, determination, fortitude, mettle, spirit; informal guts, spunk; Brit. informal bottle.
spinal.