Why is the ninth month called September?
1580s, from Latin, from Greek dialysis "dissolution, separation" (of the disbanding of troops, a divorce, etc.), from dialyein "dissolve, separate," from dia- "apart" + lyein "loosen" (see lose). Used originally in logic and grammar; chemistry sense is first recorded 1861, medicine 1914. Related: Dialytic.
dialysis 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. Also called diffusion.