ground plan

WordReference Random House Unabridged Dictionary of American English © 2025

ground′ plan′, 

1. Also called groundplot. the plan of a floor of a building.
2. first or fundamental plan.
• 1725–35

Collins Concise English Dictionary © HarperCollins Publishers::

ground plan noun

1. a drawing of the ground floor of a building, esp one to scale
   See also plan3
   Compare elevation5
2. a preliminary or basic outline