instrument

A tool or implement used to do or facilitate work, especially a small precision tool used by a professional.

A device for recording, measuring, or controlling, especially such a device functioning as part of a control system.

A device for playing or producing music.

A means by which something is done; an agency.

One used by another to accomplish a purpose; a dupe.

A legal document, especially one that represents a right of payment or conveys an interest, such as a check, promissory note, deed, or will.

To provide or equip with instruments.

To compose or arrange for performance.

In music, to compose or arrange for instruments, especially for an orchestra; score.

Something that serves as a means to the effecting of an end; anything that contributes to the production of an effect or the accomplishment of a purpose; a means; an agency.