bad actor

noun

plural bad actors
: a person, group, country, etc. who purposely and usually repeatedly engages in very bad behavior (such as committing crimes or causing harm to others)
Giving users a way to prove that they're being harassed with, say, a screenshot or some other form of authentication could help Twitter catch bad actors, even after they've covered their tracks.Issie Lapowsky
A perennial diplomatic bad actor, North Korea has already rattled its sabers at the opening of the Obama administration.Alex Kingsbury
"We've got to break away from the notion," as the U.A.W.'s [United Auto Workers] director of public relations, Peter G. Laarman, puts it, "that labor is a 'bad actor' in the economy. …"Harry Stein
also : something that causes trouble, danger, or a problem
The bad actor in male pattern hair loss is DHT, a metabolic product of testosterone. Jane E. Brody
We have special ducts throughout the vapor bath that carry away all the toxic bad actors. PC Today

Examples of bad actor in a Sentence

Recent Examples on the Web
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Schmidt warned that without enforcement, these rogue models could spread unchecked and be used for harm by bad actors. Kurt Knutsson, FOXNews.com, 17 Oct. 2025 Hackers, scammers and online propagandists are increasingly using large language models (LLMs) as part of their operations, and OpenAI releases a report each quarter detailing how those bad actors have tried to exploit versions of ChatGPT. Jasmine Cui, NBC news, 10 Oct. 2025 Secret systems give bad actors a place to hide. MSNBC Newsweek, 8 Oct. 2025 That lack of federal action could be leaving the door open for more bad actors to take advantage of the political moment to target immigrants, some lawmakers warn. Allison Gordon, CNN Money, 2 Oct. 2025 See All Example Sentences for bad actor

Word History

First Known Use

1879, in the meaning defined above

Time Traveler
The first known use of bad actor was in 1879

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Cite this Entry

“Bad actor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/bad%20actor. Accessed 23 Oct. 2025.

Last Updated: - Updated example sentences
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