HP Sassoon(1) 202.15 :חיותא דמיתבר {{מן עילעין}} שדרא דילה ואיפסיק חוטא דשדר̇א̇ <דבין חומרתא> לחומרתא‏ : an animal whose spine is broken from (its) ribs, and the spinal cord was broken between one vertebra and another
See the entire entry for šḏar, šiḏrā n.m. spine