A process in which a solid or liquid, β, is covered with a liquid, α, both of which were initially in contact with a gas or liquid, δ, without changing the area of the αδ-interface.
Source:
PAC, 1972, 31, 577. 'Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry' on page 598 (https://doi.org/10.1351/pac197231040577)