membrane

noun5

1. •
   A flexible enclosing or separating tissue forming a plane or film and separating two environments.
2. •
   A mechanical, thin, flat flexible part that can deform or vibrate when excited by an external force.
3. •
   A flexible or semiflexible covering or waterproofing whose primary function is to exclude water.

   • Then they backed the membrane with a gel matrix containing a perfluorocarbon (PFC) propellant and fluorescent "nanobullets" about a micron wide, and hit it with ultrasound. — 2016
4. •
   A microscopic double layer of lipids and proteins forming the boundary of cells or organelles.
5. •
   A piece of parchment forming part of a roll.