instrument
/ˈɪnstrumənt; `ɪnstrəmənt/ n
1 implement or apparatus used in performing an action, esp for delicate or scientific work 器具; 器械; 仪器
a surgicalinstrument, eg a scalpel 外科器械（如手术刀）
an opticalinstrument, eg a microscope 光学仪器（如显微镜）
instruments of torture 刑具.
2 apparatus for producing musical sounds, eg a piano, violin, flute or drum 乐器（如钢琴、 小提琴、 笛或鼓）
learning to play an instrument 学习演奏乐器
the instruments of the orchestra 演奏管弦乐的乐器.
3 measuring device giving information about the operation of an engine, etc or in navigation （发动机等或航海、 航空中用的）测量仪器, 仪表
a ship's instruments 船用测量仪器
[attrib 作定语]
an instrument panel 仪表盘. =>Usage at machine 用法见machine.
4
(a) ~ of sb/sth person used and controlled by another person, organization, etc, often without being aware of it 受人利用或控制的人（常为不自觉的）
We humans are merely the instruments of fate. 我们人类只不过是天命的工具.
(b) ~ of sth person or thing that brings sth about 促成某事的人或物
The organization he had built up eventually became the instrument of his downfall. 他创建起来的组织到头来却成为促使他倒台的根本原因了.
5 ~ (of sth) formal (esp legal) document 正式的（尤指合法的）文件、 文书
The king signed the instrument of abdication. 国王签署了逊位的文告.