keyboard 1. the row or set of keys on a piano, organ, or the like. 2. a set of keys, usually arranged in tiers, for operating a typewriter, typesetting machine, computer terminal, or the like. 3. any of various musical instruments played by means of a pianolike keyboard, as a piano, electric piano, or organ.
these would be the appropriate definitions for a Computer monitor:
a. a component, as a CRT, with a screen for viewing data at a computer terminal. b. a control program. Compare operating system. c. a group of systems used to measure the performance of a computer system.