di·al·y·sis (dī-āl'ĭ-sĭs) n.
pl.di·al·y·ses (-sēz')
The separation of smaller molecules from larger molecules or of dissolved substances from colloidal particles in a solution by selective diffusion through a semipermeable membrane.
Hemodialysis.
[Greek dialusis, separating, dissolution, from dialūein, to break up, dissolve : dia-, apart; see dia- + lūein, to loosen; see leu- in Indo-European roots.] di'a·lyt'ic (-ə-lĭt'ĭk) adj., di'a·lyt'i·cal·ly adv.