The crossword solution for the term SUFFIX WITH CYTO- OR PROTO- is PLASM. Plasm is a suffix that is used to describe a substance or material, such as protoplasm or cytoplasm. Protoplasm is the living material inside a cell, while cytoplasm is the material that surrounds the nucleus of a cell. Both protoplasm and cytoplasm are composed of plasm, which is a combination of proteins, lipids, carbohydrates, and other molecules.