The uptake of water by substances that do not dissolve in water, so that the process results in swelling of the substances, is called

Imbibition is the absorption of water by hydrophilic colloids (like cellulose, starch, proteins) without dissolution, causing them to swell. Osmosis requires a semipermeable membrane and solute concentration difference. Diffusion is movement of molecules from high to low concentration. Capillarity is water movement in narrow tubes due to surface tension.