Mono- is a prefix meaning "one."

Monomolecular = consisting of one molecule.

fat.

Actually detergents ;

it's 2 lipid monomolecular layers of lipids on either side of a monomolecular bubble of water.

Frederick Mayhew Fowkes has written:

'Monomolecular films adsorbed at the solution-solid interface' -- subject(s): Adsorption, Capillarity

That's the structure of a stable "soap bubble",

it's the surface tension of the monomolecular layer of water between them that holds cells (and you) together.

Copper is more electrically conductive than aluminum (this is because aluminum forms a monomolecular layer of non-conductive aluminum oxide on its surface).