• (cell membrane) Lipid and protein containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells; in most types of microbial cells it is bordered externally by the cell wall.
  CRISP Thesaurus
  National Institutes of Health, 2006
• (cell membrane) The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• Cell component which has as its parts a maximal phospholipids bilayer and two or more types of protein embedded in the bilayer. Examples: plasma membrane of hepatocyte, plasma membrane of muscle cell, plasma membrane of erythrocyte.
  Foundational Model of Anatomy
  University of Washington, 2017
• Cell part that surrounds the cytoplasm.
  Digital Anatomist
  University of Washington, 2003
• The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.
  Gene Ontology Dictionary
  Gene Ontology Consortium, 2021
• The outer membrane of a cell.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• The semipermeable membrane that encloses the cytoplasm of a cell.
  NCI
  U.S. National Cancer Institute, 2021
• Cell membrane, thin membrane that surrounds every living cell, delimiting the cell from the environment around it. Enclosed by this cell membrane (also known as the plasma membrane) are the cell's constituents, often large, water-soluble, highly charged molecules such as proteins, nucleic acids...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2025