1. A tool or implement used to do or facilitate work, especially a small precision tool used by a professional: sterilized the scalpel and other surgical instruments.
2. A device for recording, measuring, or controlling, especially such a device functioning as part of a control system.
3. Music A device designed to enable a person to make musical sounds, as by blowing into it, striking it, depressing the keys on a keyboard, or plucking, strumming, or running a bow over strings.
4. A means by which something is done; an agency: "The gods are just, and of our pleasant vices / Make instruments to plague us" (Shakespeare).
5. One used by another to accomplish a purpose; a dupe.
6. A legal document, especially one that represents a right of payment or conveys an interest, such as a check, promissory note, deed, or will.
tr.v. (-mĕnt′) in·stru·ment·ed, in·stru·ment·ing, in·stru·ments
1. To provide or equip with instruments.
2. Music To compose or arrange for performance.
[Middle English, from Old French, from Latin īnstrūmentum, tool, implement, from īnstruere, to prepare; see INSTRUCT.]
(click for a larger image)instrument
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.