Definition of: instrument

(in′strə·mənt) noun
1. A means by which work is done; an implement or tool, especially a device or mechanism for scientific or professional purposes, as distinguished from an apparatus, tool, or machine for industrial use.
2. Any means of accomplishment: The hands are instruments of the will.
3. A mechanical or other contrivance for the production of musical sounds.
4. A person doing the will of another.
5. Law A formal document, as a contract, deed, etc. See synonyms under AGENT, RECORD, TOOL.
—v.t.
1. Law To draw up an instrument.
2. Music To orchestrate. [<L instrumentum <instruere fit out, INSTRUCT]