unethical
Americanadjective
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lacking moral principles; unwilling to adhere to proper rules of conduct.
-
not in accord with the standards of a profession.
She treated patients outside the area of her training, and the appropriate medical organization punished her unethical behavior.
adjective
Other Word Forms
Etymology
Origin of unethical
Compare meaning
How does unethical compare to similar and commonly confused words? Explore the most common comparisons:
Explanation
Eating the last cookie without sharing? That's just mean. But if you stole that cookie and then lied about it, that would be morally wrong, or unethical. The prefix un- means "not," so something or someone who's unethical is literally "not ethical." In other words, that someone is lacking principles or morals. Because being unethical involves going against social or professional expectations of what's right, it's a word that's often used to describe bad behavior or immoral conduct. So like the great philosophers, you can decide if Cookie Monster has an ethics problem — or just bad eating habits.
Vocabulary lists containing unethical
Even More Negative Words to Describe a Person
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Power Prefix: un-
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The Phantom Tollbooth
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
She also scorched the DOJ lawyers—and specifically one high-ranking official, Lisa K. Hsiao—for deeply unethical behavior.
From Slate • May 18, 2026
According to reporting from Politico, at least one travel-related company declined to sponsor the venture after concluding it was unethical.
From Salon • May 18, 2026
They also ignored that it’s unethical to give patients with fatal diseases a placebo when a treatment has shown promise in early-stage trials.
From The Wall Street Journal • May 8, 2026
Private-equity funds have also been accused of unethical behavior in their aggressive pursuit of profits at all costs.
From MarketWatch • Apr. 24, 2026
Later that year, a Harvard anesthesiologist named Henry Beecher published a study in the New England Journal of Medicine showing that Southam’s research was only one of hundreds of similarly unethical studies.
From "The Immortal Life of Henrietta Lacks" by Rebecca Skloot
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
