membrane

The word “membrane” means a thin, flexible layer of tissue that lines or separates parts of an organism. In plain terms, a thin, flexible layer that covers or separates something — used both biologically (cell membranes) and in building materials.

“Membrane” is pronounced MEHM-brayn (/ˈmɛm.bɹeɪn/ in IPA).

Here is “membrane” used in a sentence: “The cell membrane controls what enters and leaves the cell.”

“Membrane” is a noun.

The word “membrane” comes from Latin. From Latin membrana ("skin covering a body part"), from membrum ("limb, body part").

“Membrane” is an uncommon word in modern English.

“Membrane” has 2 distinct senses listed in this dictionary. The most common is: a thin, flexible layer of tissue that lines or separates parts of an organism.

A membrane is specifically a thin, flexible layer that lines or separates parts of an organism, such as a cell membrane or mucous membrane. Tissue is a broader biological term for any group of similar cells performing a function together, and a membrane is just one particular form that tissue can take.

A waterproofing membrane is a thin flexible sheet used as a barrier to keep moisture out of a structure, commonly installed under roofing, flooring, or foundations. This is a non-biological use of the same word, applying the general idea of a thin protective sheet to building materials.

Membrane specifically describes a thin, flexible sheet-like layer, while barrier is a more general term for anything that blocks or separates, thin or thick, flexible or rigid. Every membrane can act as a barrier, but not every barrier is a membrane.