ninja

noun

nin·​ja ˈnin-jə How to pronounce ninja (audio)
-(ˌ)jä
plural ninja also ninjas
: a person trained in ancient Japanese martial arts and employed especially for espionage and assassinations

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 ancient Japan 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 the arts of combat and self-defense we associate with modern martial arts. Popular legends still identify 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
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The anthology film follows three human warriors in history – a Viking warrior woman, a ninja in feudal Japan and a World War II ace – being stalked as prey by alien hunters with high-tech weaponry and a mean streak. Brian Truitt, USA Today, 14 June 2025 The 90-minute film follows three different warriors throughout history: A Viking raider and her son on a quest for revenge; two Japanese brothers—a ninja and a Samurai—who turn on one another in a war of succession; and a WWII pilot who investigates an extraterrestrial threat. Erik Kain, Forbes.com, 6 June 2025 These include a raccoon dressed as a ninja with a katana and a Jingasa hat, which should be officially added to the game before the next update. John Mac Ghlionn, Newsweek, 14 Jan. 2025 This anthology film tells of three fierce human warriors – a vengeful Viking raider, a ninja in feudal Japan and an Allied pilot in World War II – who face off against a deadly alien hunter with otherworldly weaponry and a mean streak. Brian Truitt, USA Today, 13 May 2025 See All Example Sentences for ninja

Word History

Etymology

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

First Known Use

1964, in the meaning defined above

Time Traveler
The first known use of ninja was in 1964

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Cite this Entry

“Ninja.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ninja. Accessed 29 Jun. 2025.

Kids Definition

ninja

noun
nin·​ja ˈnin-jə How to pronounce ninja (audio)
-(ˌ)jä
plural ninja also ninjas
: a person trained in ancient Japanese arts of combat and self-defense and employed especially for espionage and assassinations
Last Updated: - Updated example sentences
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