Gathers in a condensed layer

• Collects in condensed form
• Gathers on the surface, as a layer of molecules
• Takes up onto the surface
• Holds on a surface, as molecules
• What charcoal does to gases
• Causes to condense on a surface
• Condenses on a surface

Wiktionary Word definitions in Wiktionary
vb. (en-third-person singular of: adsorb)