A highly intelligent person, especially one who plans and directs a complex or difficult project: the mastermind of a robbery.
tr.v. mas·ter·mind·ed, mas·ter·mind·ing, mas·ter·minds
To direct, plan, or supervise (a project or activity).
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.