From Middle English instrument, from Old French instrument, from Latin īnstrūmentum,

From īnstruō + -mentum.

• IPA: /ˈɪnstɹəmənt/, /ˈɪnstɹʊmənt/

instrument (plural instruments)

1. A device used to produce music.

   The violinist was a master of her instrument.

2. A means or agency for achieving an effect.
   • 1904–1905, Baroness Orczy [i.e., Emma Orczy], “The Tremarn Case ↗”, in The Case of Miss Elliott, London: T[homas] Fisher Unwin, published 1905, →OCLC ↗; republished as popular edition, London: Greening & Co., 1909, OCLC 11192831 ↗, quoted in The Case of Miss Elliott (ebook no. 2000141h.html), Australia: Project Gutenberg of Australia, February 2020:

     “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.  […] ”

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. (legal) 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. (figuratively) A person used as a mere tool for achieving a goal.
   • c. 1596 (date written), William Shakespeare, “The Life and Death of King Iohn”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, [Act V, scene ii]:

     Or useful serving man and instrument, / To any sovereign state.

   • 1670, John Dryden, The Conquest of Granada:

     The bold are but the instruments o' the wise.

• See also Thesaurus:instrument

• instrumental

• French: instrument
• German: Instrument, Musikinstrument
• Italian: strumento
• Portuguese: instrumento
• Russian: инструме́нт
• Spanish: instrumento

• German: Instrument, Meßinstrument
• Italian: strumento
• Portuguese: instrumento, aparelho
• Russian: прибо́р

• German: Werkzeug, Instrument
• Italian: strumento
• Portuguese: instrumento
• Russian: инструме́нт
• Spanish: instrumento, herramienta

• French: acte
• German: Dokument, Urkunde
• Russian: инструме́нт
• Spanish: instrumento

• German: Handlanger
• Spanish: instrumento

instrument (instruments, present participle instrumenting; simple past and past participle instrumented)

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

• (to apply measuring devices) measure, supervise
• (to devise, conceive)
• (to perform on an instrument) play
• (to prepare for an instrument) arrange