means The movement of a solvent (usually water) through a semipermeable membrane from a region of lower solute concentration to one of higher concentration, tending to equalize the two — or, loosely, the gradual unconscious absorption of knowledge or ideas.

from Coined in the 19th century by scientists studying how fluids creep through membranes. It traces back to the Greek 'ōsmos,' meaning 'a push' or 'thrust' (from 'ōthein,' to push), so the word literally carries the sense of something being shoved through a barrier. An earlier form, 'endosmose,' came via French before English smoothed it into the tidier 'osmosis.'