membrane

American  

[mem-breyn] / ˈmɛm breɪn /

noun

• membranes
  plural

1. Anatomy. a thin, pliable sheet or layer of animal or vegetable tissue, serving to line an organ, connect parts, etc.

2. Cell Biology. the thin, limiting covering of a cell or cell part.

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membrane British  

/ ˈmɛmbreɪn /

noun

1. any thin pliable sheet of material

2. a pliable sheetlike usually fibrous tissue that covers, lines, or connects plant and animal organs or cells

3. biology a double layer of lipid, containing some proteins, that surrounds biological cells and some of their internal structures

4. physics a two-dimensional entity postulated as a fundamental constituent of matter in superstring theories of particle physics

5. a skin of parchment forming part of a roll

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membrane Scientific  

/ mĕm′brān′ /

1. A thin, flexible layer of tissue that covers, lines, separates, or connects cells or parts of an organism. Membranes are usually made of layers of phospholipids containing suspended protein molecules and are permeable to water and fat-soluble substances.

2. See cell membrane

3. Chemistry A thin sheet of natural or synthetic material that is permeable to substances in solution.

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Other Word Forms

Derived Forms

• intermembrane
  adjective
• membraneless
  adjective

Inflected Forms

Nouns

• membranes
  plural

Etymology

Origin of membrane

1375–1425; late Middle English; Middle English membraan parchment < Latin membrāna. See member, -an

Explanation

A membrane is a thin layer of something. For an example of a membrane, you don’t have to look far: your skin is a kind of membrane. Membranes are thin and flexible, but usually still strong enough to protect what’s inside or underneath them. Biologists often study membranes, such as those that surround your cells and organs. There are also membranes that don’t have anything to do with biology. A high-tech jacket might have a waterproof membrane to keep you dry in the rain.

Example Sentences

See Examples For:

membrane membranes

Those that make a sound when a stretched membrane is struck or otherwise manipulated—think, for instance, of a drum—they called membranophones.

From The Wall Street Journal ● Aug. 7, 2026

She shared that her cancer had spread to her peritoneum, a membrane that lines the abdominal and pelvic cavities and protects internal organs.

From BBC ● Aug. 6, 2026

Those cells then transfer the membrane complex carrying the protein fragment to cDC2 cells through an already known process called "cross dressing."

From Science Daily ● Jul. 9, 2026

According to the study, the buildup of toxic proteins destabilizes the outer membrane of the nucleus, causing it to shrink and eventually disintegrate.

From Science Daily ● Jul. 5, 2026

The cell was a beaker of chemicals, biochemists argued, a pouch of compounds bound by a membrane that were reacting to produce a phenomenon called “life.”

From "The Gene" by Siddhartha Mukherjee

Collagen membranes generated a greater amount of bone overall, but the bone formed with the keratin scaffolds was more organized and structurally secure.

From Science Daily ● Aug. 12, 2026

The measurements revealed that the strong bonding between the membranes does more than simply hold them together.

From Science Daily ● Aug. 3, 2026

PEs are a class of lipid, or fat molecule, found in cell membranes throughout the body.

From Science Daily ● Jul. 31, 2026

"A defining feature of the chip was precision current injection, which we used to permeabilize neuronal membranes for intracellular access," Ham said.

From Science Daily ● Jul. 9, 2026

All the gooey membranes popped and the tunnels collapsed, billowing plumes of dust.

From "Blood of Olympus" by Rick Riordan

Related Words

• sheath
• sheet