<p><strong>Noun</strong></p><ul><li>Physical Chemistry, Cell Biology: the tendency of a fluid, usually water, to pass through a semipermeable membrane into a solution where the solvent concentration is higher, thus equalizing the concentrations of materials on either side of the membrane.</li><li>the diffusion of fluids through membranes or porous partitions.</li><li>Compare endosmosis, exosmosis.</li><li>a subtle or gradual absorption or mingling: He never studies but seems to learn by osmosis.</li></ul>