nin·​ja | \ ˈnin-jə How to pronounce ninja (audio) , -(ˌ)jä\
plural ninja also ninjas

Definition of ninja

: a person trained in ancient Japanese martial arts and employed especially for espionage and assassinations

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Did You Know?

Ninjas may seem mysterious, but the origin of their name is not. The word ninja derives from the Japanese characters "nin" and "ja." "Nin" initially meant "persevere," but over time it developed the extended meanings "conceal" and "move stealthily." In Japanese, "ja" is the combining form of sha, meaning "person." Ninjas originated in the mountains of Japan over 800 years ago as practitioners of ninjutsu, a martial art sometimes called "the art of stealth" or "the art of invisibility." They often served as military spies and were trained in disguise, concealment, geography, meteorology, medicine, and also other martial arts. Popular legends still associate them with espionage and assassinations, but modern ninjas are most likely to study ninjutsu to improve their physical fitness and self-defense skills.

Examples of ninja in a Sentence

Recent Examples on the Web

Anthem’s suit collection Anthem continues to look quite a bit like Warframe, this week showing off its own lineup of flippy ninja and larger (more boring) robots. Hayden Dingman, PCWorld, "This week in games: Red Dead Redemption 2 PC release hints, No Man's Sky heads under the sea," 2 Nov. 2018 But the little shoe-tying ninja doesn't want to take all the glory. Kelly O'sullivan, Woman's Day, "This 5-Year-Old's Genius Method For Tying Shoes Is Going Mega Viral," 25 Jan. 2017 The tines start turning dirt, wheeling through the earth like ninja throwing stars. Roy Berendsohn, Popular Mechanics, "The Year of the Tractor," 7 May 2016 Unusual or replica weapons Don’t pack metal ninja stars or ornamental knives with blades hidden in canes or hair brush handles; people have tried to bring such items but the TSA always finds them — and dumps them. Fox News, "6 things to know the next time you go through airport security," 16 May 2018 For going on two decades now, the collaborative line between Adidas and Japanese flex god Yohji Yamamoto has artfully and innovatively explored the boundaries where high-performance athletic function meets high-fashion streetwear-ninja form. Yang-yi Goh, GQ, "The Best Backpacks for Work Will Make You Feel Like a Boss," 14 June 2018 The player advances to higher ninja levels by holding poses for longer periods of time. Sarah Deweerdt, Science | AAAS, "Can science-based video games help kids with autism?," 22 June 2018 The store is a dark forest of crepe dangling down from the ceiling into a crush of dinosaur piñatas and ninja piñatas and seven-pointed stars that look like Sputniks. Christopher Borrelli,, "Trump piñatas a hit across cultures," 16 May 2018 But its eerie grin isn’t even the most unique feature of this deep sea ninja. Katherine J. Wu, Smithsonian, "Why Bioluminescence Evolved to Be Red Light, and Blue," 26 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ninja.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of ninja

1964, in the meaning defined above

History and Etymology for ninja

Japanese, from nin- persevere, conceal, move stealthily + -ja person

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Time Traveler for ninja

The first known use of ninja was in 1964

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English Language Learners Definition of ninja

: a fighter who is trained in the Japanese martial arts


nin·​ja | \ ˈnin-jə How to pronounce ninja (audio) \
plural ninja also ninjas

Kids Definition of ninja

: a person trained in ancient Japanese martial arts who works as a spy and assassin especially in the past

Comments on ninja

What made you want to look up ninja? Please tell us where you read or heard it (including the quote, if possible).


to move with exaggerated bouncy motions

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