9. instrument to arrange (a composition) for musical instruments; orchestrate.
Etymology: (1250–1300; ME < L instrūmentum equipment, der. of instruere to equip; see instruct)
Definition of 'instrument'
Princeton's WordNet
1. (noun)instrument a device that requires skill for proper use
2. (noun)instrument, tool the means whereby some act is accomplished "my greed was the instrument of my destruction"; "science has given us new tools to fight disease"
3. (noun)instrument, pawn, cat's-paw a person used by another to gain an end
4. (noun)legal document, legal instrument, official document, instrument (law) a document that states some contractual relationship or grants some right
5. (noun)instrumental role, instrument the semantic role of the entity (usually inanimate) that the agent uses to perform an action or start a process
6. (verb)musical instrument, instrument any of various devices or contrivances that can be used to producemusical tones or sounds
7. (verb)instrument equip with instruments for measuring, recording, or controlling
8. (verb)instrument, instrumentate write an instrumental score for
1. (noun)instrument an object you use to producemusic to play an instrument
2. instrument a device for measuring the instruments in the airplane's cockpit; an instrument panel
3. instrument a tool or device designed to help sb do skilled work surgical instruments
4. instrument sb or sth used to achieve a goal She encouraged her followers to be instruments of peace.
Definition of 'instrument'
Webster Dictionary
1. (noun)instrument that by means of which any work is performed, or result is effected; a tool; a utensil; an implement; as, the instruments of a mechanic; astronomical instruments
3. (noun)instrument a writing, as the means of givingformalexpression to some act; a writing expressive of some act, contract, process, as a deed, contract, writ, etc
4. (noun)instrument one who, or that which, is made a means, or is caused to serve a purpose; a medium, means, or agent
5. (verb)instrument to perform upon an instrument; to prepare for an instrument; as, a sonata instrumented for orchestra
Definitions of instrument 
Afrikaans: instrument
Arabic: وسيلَه، واسِطَه، أداه
Bulgarian: инструмент
Brazilian: instrumento
Czech: nástroj
German: das Instrument
Danish: instrument
Greek: όργανο
Spanish: instrumento
Estonian: aparaat
Farsi: ابزار
Finnish: instrumentti
French: instrument
Hebrew: מַכשִיר
Hindi: उपकरण
Croatian: alat, oruđe
Hungarian: műszer
Indonesian: alat
Icelandic: tæki, áhald
Italian: strumento
Japanese: 器具
Korean: 도구, 기구
Lithuanian: įrankis, instrumentas
Latvian: instruments
Malay: peralatan
Dutch: instrument
Norwegian: instrument, redskap
Polish: narzędzie, przyrząd
Persian: ابزار
Pashto: اسباب،اّله، افزار سامان، 
Portuguese: instrumento
Romanian: instrument
Russian: инструмент, прибор
Slovak: nástroj; prístroj
Slovenian: pripomoček
Serbian: instrument
Swedish: instrument
Thai: เครื่องตรวจวัด
Turkish: alet, araç, aygıt
Taiwanese: 儀器
Ukrainian: інструмент; прилад
Urdu: اوزار
Vietnamese: dụng cụ
Chinese: 仪器
