1. A person who behaves in the manner of a character, usually by reciting scripted dialogue, in order to entertain an audience, especially in a play, movie, or television show.
2. One who takes part; a participant: "France, Britain ... and any other external actors now involved ... in the affairs of the continent" (Helen Kitchen).
a. One, such as the manager of a business, who acts for another.
b. In civil law, the plaintiff in an action.
[Middle English actour, doer, probably from Latin āctor, from āctus, past participle of agere, to drive, do; see ag- in the Appendix of Indo-European roots.]
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.