es·pi·o·nage (ĕspē-ə-näzh′, -nĭj)
The practice of spying or of using spies to obtain secret information, especially regarding a government or business.
[French espionnage, from espionner, to spy, from Old French espion, spy, from Old Italian spione, of Germanic origin; see spek- 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.
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.