Absorbent Posted on 1st November 201521st October 2020 by ThePD (The Project Definition) Absorbent is a substance that extracts one or more substances from a gas or liquid medium on surface contact. Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window) Related Posted in Substance and tagged chemical, substance. ThePD (The Project Definition) ThePD has been developing the Preferred Project Definitions based on the actual project execution and operation experiences and knowledge with the Project Language, and sharing with you daily basis.