keyboard

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A panel of buttons used for typing and performing other functions on a computer or typewriter.
• noun A row of levers that are depressed with the fingers to produce or modulate the sound of an instrument, such as a piano or organ.
• noun Any of various instruments, played by means of a musical keyboard, often connected to a synthesizer or amplifier.
• transitive verb To set (copy) by means of a keyed typesetting machine.
• transitive verb To enter (text or data) into a computer by means of a keyboard.
• transitive verb Music To play (a composition) on a piano or keyboard.

from The Century Dictionary.

• noun In the organ, pianoforte, and similar instruments, as the harpsichord, clavichord, etc., the series or horizontal row of finger-levers or digitals (usually called keys), by depressing which the performer causes the pipes, strings, or reeds to produce tonos.
• noun Pedal keyboards in the organ are called radiating when the keys are made to converge somewhat below the player's seat, like the ribs of a fan, and concave when the general level of the inner keys is lower than that of the outer ones. In the best organs the pedal keyboard is both concave and radiating.
• noun The set of keys for operating the letters of a type-writing or type-settingmachine.

from the GNU version of the Collaborative International Dictionary of English.

• noun The whole arrangement, or one range, of the keys{3} of an organ, piano, typewriter, etc.; that part of a device containing the keys{3} used to operate it.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A set of keys used to operate a typewriter, computer etc.
• noun music A component of many instruments including the piano, organ, and harpsichord consisting of usually black and white keys that cause different tones to be produced when struck.
• noun music A device with keys of a musical keyboard, used to control electronic sound-producing devices which may be built into or separate from the keyboard device.
• verb intransitive To type on a computer keyboard.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun device consisting of a set of keys on a piano or organ or typewriter or typesetting machine or computer or the like
• noun holder consisting of an arrangement of hooks on which keys or locks can be hung