kičma

1. spine; backbone
   Od sedenja za kompjuterom boli me kičma. — My spine hurts from sitting at the computer.
2. (of character) backbone; spine
   Taj političar nema nimalo kičme. — That politician has no backbone at all.
3. backbone
   Mala preduzeća su kičma naše privrede. — Small businesses are the backbone of our economy.

Kralježnica is Croatian; in Serbia people say kičma or kičmeni stub.