1. A theatrical performer.
2. One who takes part; a participant: "France, Britain . . . and any other external actors now involved . . . in the affairs of the continent" (Helen Kitchen).
3. Law. One, such as the manager of a business, who acts for another.

[Middle English actour, doer, probably from Latin āctor, from āctus, past participle of agere, to drive, do.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.