- the principal story of a large building, as of a palace or villa.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- architect the main floor of a large house, containing the reception rooms: usually of lofty proportions
Word Origin for piano nobile
Italian: great floor
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012