(n): an instrumentality invented for a particular purpose
(n): the means whereby some act is accomplished
(n): how a result is obtained or an end is achieved
(n): a person used by another to gain an end
(n): a person who contributes to the fulfillment of a need or furtherance of an effort or purpose
(n): (law) a document that states some contractual relationship or grants some right
(n): writing that provides information (especially information of an official nature)
(n): the semantic role of the entity (usually inanimate) that the agent uses to perform an action or start a process
(n): (linguistics) the underlying relation that a constituent has with the main verb in a clause
(n): any of various devices or contrivances that can be used to produce musical tones or sounds
(n): an instrumentality invented for a particular purpose
(v): equip with instruments for measuring, recording, or controlling
(v): provide with (something) usually for a specific purpose
(v): write an instrumental score for
(v): write music
(v): address a legal document to
(v): put an address on (an envelope)
As a verb (well, a form derived from use as a verb anyway): 'Scientists would like to send an instrumented balloon to Titan'