Cohesion Posted on 5th November 201521st July 2021 by ThePD (The Project Definition) Cohesion is the situation when the members of a group are united that is the measure of how well molecules stick to each other or group together. 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 Science and tagged chemistry. 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.