instrument

noun

• 1a tool or implement, especially one for precision work:a surgical instrument instruments of torture writing instruments

• 2a measuring device used to gauge the level, position, speed, etc. of something, especially a motor vehicle or aircraft: a new instrument for measuring ozone levels myriad instruments and switches

• 3 (also musical instrument) an object or device for producing musical sounds:a percussion instrument

• 4a means of pursuing an aim:the failure of education as an instrument of social reform
• a person who is exploited or made use of:he was a mere instrument acting under coercion

• 5a formal or legal document:execution involves signature and unconditional delivery of the instrument

verb

• equip (something) with measuring instruments: engineers have instrumented rockets to study the upper atmosphere a DC-8 aircraft instrumented as a flying laboratory