cytoplasm cy·to·plasm (sī'tə-plāz'əm)
The protoplasm outside a cell nucleus.
The jellylike material that makes up much of a cell inside the cell membrane, and, in eukaryotic cells, surrounds the nucleus. The organelles of eukaryotic cells, such as mitochondria, the endoplasmic reticulum, and (in green plants) chloroplasts, are contained in the cytoplasm. The cytoplasm and the nucleus make up the cell's protoplasm. See more at cell.