host intracellular organelle host intracellular membrane-bounded organelle host intracellular membrane-enclosed organelle Organized structure of distinctive morphology and function, as found in host cells, bounded by a single or double lipid bilayer membrane and occurring within the cell. Includes the nucleus, mitochondria, plastids, vacuoles, and vesicles. Excludes the plasma membrane. The host is defined as the larger of the organisms involved in a symbiotic interaction. cellular_component GO:0033648