Webster's Revised Unabridged Dictionary · 1913

Piano

Piano , adjective and adverb

[Italian, even, smooth, soft, from Latin planus even, level.]

(Music) Soft; -- a direction to the performer to execute a certain passage softly, and with diminished volume of tone. (Abbrev. p.)

Piano , noun

[Italian piano soft (from Latin planus even, smooth; see Plain, a.) + Italian forte strong, from Latin fortis (see Fort).]

(Music) A well-known musical instrument somewhat resembling the harpsichord, and consisting of a series of wires of graduated length, thickness, and tension, struck by hammers moved by keys.
Collocations (4)
Dumb piano , See Digitorium.
Grand piano , See under Grand.
Square piano , one with a horizontal frame and an oblong case.
Upright piano , one with an upright frame and vertical wires.

Also: Pianoforte