What does membrane mean?
A membrane is a thin sheet or layer that covers, separates, or forms part of a structure. In biological contexts, it describes the delicate layers of tissue and lipids that surround cells, line organs, and control what enters or leaves them. Membranes can also be manufactured materials used to cover surfaces, divide spaces, or provide a barrier. The word is especially useful in discussions of biology, chemistry, medicine, and materials science because it captures both the physical idea of a thin dividing layer and the functional idea of controlling exchange. In ordinary writing, membrane may be used more broadly for any protective or separating film, though it often carries a scientific or technical tone.
nounA thin, flexible sheet or layer of material that separates, covers, or forms part of a larger structure. In biology, the term refers to a specialized layer of tissue or lipid bilayer that encloses or separates cells and organs.
- A thin, flexible sheet or layer that covers, separates, or forms part of a structure.
- A biological layer or structure that encloses a cell, organ, or other bodily space and regulates the passage of substances.
- A flexible sheet of material used in construction, packaging, or as a barrier.
"The membrane surrounding the cell regulates the movement of substances into and out of it."
"A thin membrane separates the two chambers of the device."
"Researchers studied how the cell membrane controls the transport of nutrients."
Use the plural when referring to several membranes or distinct biological or physical layers.
"The cell contains membranes that regulate the movement of ions and nutrients."
From cell walls to the lining of your lungs, membranes make it possible for living systems to keep separate spaces while still exchanging what they need.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does membrane come from?
The word entered English from Latin membrana, meaning a thin skin or membrane, a diminutive related to membrum, meaning limb or part. The Latin term developed in anatomical and legal contexts to refer to a covering, skin, or dividing layer. English later extended the word to mechanical and chemical uses involving thin separating sheets.
Related word forms
How membrane is actually used
In biology, membrane usually refers to a highly organized biological layer, especially the lipid bilayer surrounding cells. In general use, it can describe any thin sheet, but it often suggests a flexible or permeable barrier. The adjective membranous means consisting of or resembling a membrane.
Easily confused with membrane
A membrane is a thin separating layer or covering, whereas a member is a person or part of a group.