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 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.
• 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.

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