harmless
Americanadjective
-
without the power or desire to do harm; innocuous.
He looks mean but he's harmless; a harmless Halloween prank.
- Synonyms:
- benign, unobjectionable, innocent, mild, inoffensive
-
without injury; unhurt; unharmed.
idioms
adjective
-
not causing any physical or mental damage or injury
-
unlikely to annoy or worry people
a harmless sort of man
Other Word Forms
- harmlessly adverb
- harmlessness noun
Etymology
Origin of harmless
Explanation
Things that can't hurt you are harmless. It might be hard for you to believe her when your sister tells you that her enormous pet snake is completely harmless. If your friend is scared of dogs, you can reassure her by saying, "Sure, he's 150 pounds and has a loud bark, but Fido is harmless!" Things that are safe or benign don't cause harm, and are therefore harmless, like your dad's harmless teasing or a compostable paper plate that's harmless to the environment. The word harmless originally meant "uninjured," or "not harmed," and came to mean "undamaged" by the end of the 1300s.
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.
The British-born Elsie thought she was married to a harmless teacher until she smelled something awful coming from the crawl space beneath their house.
From The Wall Street Journal • May 1, 2026
According to OpenAI, "a single 'little goblin' in an answer could be harmless, even charming," but the uptick in their appearance across output warranted investigation.
From BBC • Apr. 30, 2026
"The golden oyster mushroom may look harmless on a log, but it appears to be a strong competitor in the forest," she said.
From Science Daily • Apr. 24, 2026
“They can seem so small and harmless, but even those little things add up. They’re felt. It’s part of feeling unsafe in the world.”
From Los Angeles Times • Apr. 22, 2026
I mean to make my news sound scary, but a ghost now seems harmless compared to what we just heard.
From "Before We Were Free" by Julia Alvarez
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.
