If you mean as in the cartilage between the bones in the spine - it's 'disc'
"Disk" is Spanish is "el disco".
how to spell
A field spell
The medical problems that can be fixed by a cervical disk surgery are all back problems such as rupturing a disk in one's back which can cause the need for surgery.
medical crew
it can spell piperacillin, an antibiotic
That sentence makes no sense, but, "Give you that disk, please."
The acronym 'CD', often refers to 'compact disk'.
sense as in common sense or a sense of style or the five senses
sense*
I sense you're talking about the infinite disk, the hyperbolic disk or the Poincare disk. The limit of the circumference is infinite and a real number and is not actually part of the hyperbolic plane.
The word disk, as it applies to the back, refers to elastic tissue that sits between the vertebrae. These disks absorb shock during movement.