Definition of "first floor" [first floor]

• The ground floor of a building. (noun)
• Chiefly British The floor immediately above the ground floor. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The people on the first floor have too many barriers trees, etc., and most rooms on the second floor look over the South Grounds."
• "In Franklin just south of Nashville, Maggie Coyle, a 57-year-old speech pathologist, wound up with 16 inches of water inside the first floor of her home near the Harpeth River."
• "As with all the other key exhibits in the Louvre, all items on the first floor were laser-protected: as soon as a painting or sculpture was moved, it triggered an invisible laser, and steel grilles would descend at every nearby doorway, sealing in the thieves."