- somatic cell
- somatic mutation
- somatomedin
- somatostatin receptor scintigraphy
- somatotropin
- somnolence syndrome
- sonogram
- SOP
- sorafenib
- sorafenib tosylate
- sorivudine
- sorrel
- soy
- soya
- soybean
- spasm
- spastic colon
- spatial correlation
- specialist
- specific immune cell
- specificity
- SPECT
- spectroscopy
- speculum
- speech pathologist
- speech therapist
- sperm
- sperm banking
- sperm count
- sperm retrieval
- spermatic cord
- SPF
- sphenoid sinus
- sphincter
- spiculated mass
- spinal anesthesia
- spinal block
- spinal column
- spinal cord
- spinal cord compression
- spinal tap
- spindle cell cancer
- spindle cell sarcoma
- spine
- spine cancer
- spiral CT scan
- spirituality
- spleen
- splenectomy
- splenic