A device used to produce music.

A means or agency for achieving an effect.

A measuring or displaying device.

A tool or implement used for manipulation or measurement, often referred to as flight instruments in aviation.

(law) A legal document, such as a contract, deed, trust, mortgage, power, indenture, or will.

(figurative) A person used as a mere tool for achieving a goal.

(transitive) To apply measuring devices.

(transitive) To devise, conceive, cook up, plan.

To perform upon an instrument; to prepare for an instrument.