'adatom' originates from the combination of 'adsorb' and 'atom', where 'adsorb' refers to the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface.

'adatom' was coined in the 20th century to describe atoms that adhere to surfaces, particularly in the context of surface science and nanotechnology.

Initially, it meant 'an atom on a surface', and this meaning has remained consistent in modern usage.