Thickness Posted on 23rd December 20152nd June 2022 by ThePD (The Project Definition) Thickness is a distance between the opposite sides of objective. Related Definitions in the Project: The Property and Unit 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 Engineering and tagged property. 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.