A drawing showing technical details of a building, machine, etc., with unwanted details omitted, and often using symbols rather than detailed drawing to represent doors, valves, etc.
"The architect handed over the final plan for the new factory, where every valve was marked with a simple symbol instead of being drawn in full detail."
In plain English: A plan is a written or spoken list of steps you make to get something done.
"She made a detailed plan for her vacation."
Usage: Use "plan" as a noun to refer to a map or diagram viewed from above that shows the layout of a room, building, or site. Do not use it for a list of future actions, which is also called a plan but should be distinguished from this technical drawing definition.
To design (a building, machine, etc.).
"The architect spent weeks carefully planning every angle and load-bearing wall before breaking ground on the new library."
In plain English: To plan means to decide on and organize what you will do before you start.
"We plan to visit our grandparents next weekend."
Usage: Use "plan" as a verb to describe creating a detailed scheme or arrangement for future action, such as organizing an event or mapping out a strategy. Do not use it when referring specifically to the act of designing physical objects like buildings or machines, which requires a different context.
The People's Liberation Army Navy.
"The sailors on board the PLAN destroyer conducted routine maintenance during their deployment in the South China Sea."
The word "plan" comes from the French plan, which originally meant a flat surface or map. It entered English with this sense of a level ground plot derived from the Latin plānus.