1. (Science: chemistry) The accumulation or concentration of molecules of a gas or liquid on a surface in contact with the gas or liquid, resulting in a relatively high concentration of the gas or solution at the surface. Note that the accumulating molecules do not actually penetrate the substance they are on.
2. (Science: virology) The adhesion of a substance to an organic particle in a solution, for example the adhesion of a virus to a cell.
Origin: L. Sorbere = to suck