noun Cell Biology.
- the inner portion of the cytoplasm of a cell.Compare ectoplasm(def 1).
- cytology the inner cytoplasm in some cells, esp protozoa, which is more granular and fluid than the outer cytoplasmSee ectoplasm (def. 1)
- A central, less viscous portion of the cytoplasm that is distinguishable in certain cells, especially motile cells and protozoa.