instrument

Etymology

From Middle English instrument, from Old French instrument, from Latin īnstrūmentum (“an implement, tool”), From īnstruō (“build, construct; arrange”) + -mentum.

noun

1. A device used to produce music.
   The violinist was a master of her instrument.
   The Harpe. […] A harper with his wreſt maye tune the harpe wrong / Mys tunying of an Inſtrument ſhal hurt a true ſonge 1568, William Cornishe [i.e., William Cornysh], “In the Fleete Made by Me William Cornishe otherwise Called Nyshwhete Chapelman with the Most Famose and Noble Kyng Henry the VII. His Reygne the XIX. Yere the Moneth of July. A Treatise betwene Trouth, and Information.”, in John Skelton, edited by J[ohn] S[tow], Pithy Pleasaunt and Profitable Workes of Maister Skelton, Poete Laureate, Imprinted at London: In Fletestreate, neare vnto St Dunstan-in-the-West by Thomas Marshe, →OCLC; republished as Pithy Pleasaunt and Profitable Workes of Maister Skelton, Poete Laureate to King Henry the VIIIth, London: Printed for C. Davis in Pater-noster Row, 1736, →OCLC, page 290
2. A means or agency for achieving an effect.
   There the cause of death was soon ascertained ; the victim of this daring outrage had been stabbed to death from ear to ear with a long, sharp instrument, in shape like an antique stiletto, which … was subsequently found under the cushions of the hansom. … 1905, Baroness Emmuska Orczy, chapter 1, in The Tremarn Case
   On the rocky island of Tungyin, 50 miles off the coast of Red China, is the headquarters of a little-known military unit called the Anti-Communist Salvation Army. The secret army, 30,000 strong, is Chiang Kai-shek's instrument for the long-promised return to the mainland. January 11, 1963, “The World”, in Time, volume LXXXI, number 2, →ISSN, →OCLC, page 32, column 3
3. A measuring or displaying device.
   The instrument detected an increase in radioactivity.
4. A tool, implement used for manipulation or measurement.
   The dentist set down his tray of instruments.
   The scientist recorded the temperature with a thermometer but wished he had a more accurate instrument.
   1. (aviation, usually in the plural) Ellipsis of flight instrument.
      Flight within clouds must be made by reference to your instruments.
5. (law) A legal document, such as a contract, deed, trust, mortgage, power, indenture, or will.
   A bond indenture is the instrument that gives a bond its value.
   Negotiable instruments are the foundation of the debt markets.
6. (figurative) A person used as a mere tool for achieving a goal.
   The bold are but the instruments o' the wise. 1670, John Dryden, The Conquest of Granada

verb

1. (transitive) To apply measuring devices.
   an instrumented test article
2. (transitive) To devise, conceive, cook up, plan.
3. To perform upon an instrument; to prepare for an instrument.
   a sonata instrumented for orchestra