A grand piano is a large piano whose strings are set horizontally to the ground. Grand pianos are used especially for giving concerts and making recordings.
grand piano in British English
noun
a form of piano in which the strings are arranged horizontally. Grand pianos exist in three sizes
Compare baby grand, boudoir grand, concert grand, upright piano
grand piano in American English
a large piano with strings set horizontally in a wing-shaped case supported on three legs
As he showed me out of his house he gestured towards two grand pianos side by side in the room where he worked.
Times, Sunday Times (2007)
Oh, and a grand piano is not supplied, sadly.
Times, Sunday Times (2006)
There are grand pianos dotted around on landings, which look almost small, so large are the proportions of the building.
Times, Sunday Times (2008)
Here, after a cursory audition and the purchase of his first suit, her beloved son was installed behind a large white grand piano as the teatime entertainment.