Instrument

the means whereby some act is accomplished

any of various devices or contrivances that can be used to produce musical tones or sounds

a person used by another to gain an end

(law) a document that states some contractual relationship or grants some right

the semantic role of the entity (usually inanimate) that the agent uses to perform an action or start a process

a device that requires skill for proper use

write an instrumental score for

address a legal document to

equip with instruments for measuring, recording, or controlling