im·pe·ra·tor (ĭm′pə-rätôr′, -tər)
1. An army commander in the Roman Republic.
2. The supreme power of the Roman emperor.
3. The head of state and supreme commander in the Roman Empire, in whose name all victories were won.
[Latin imperātōr; see EMPEROR.]
im·per′a·tori·al (ĭm-pĕr′ə-tôrē-əl) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.