Pronunciation: (dī-al'u-sis),[key] —n., —pl.-sesPronunciation: (-sēz").[key] 1. Physical Chem.the separation of crystalloids from colloids in a solution by diffusion through a membrane.
2. Biochem.the separation of large molecules, as proteins, from small molecules and ions in a solution by allowing the latter to pass through a semipermeable membrane.
3. Med.(in kidney disease) the process by which uric acid and urea are removed from circulating blood by means of a dialyzer.