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

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 As the staff sergeant then took off running, the man dressed as a ninja began kicking and punching doors and windows, then reportedly threw a block of asphast through a building window. Brigid Kennedy, The Week, 30 Sep. 2021 Once a new pair of bright blue sneakers were laced, Aiden jumped, giving the air a quick ninja kick before, on the encouragement of Ohonme, sprinting through the parking lot. Olivia Krauth, The Courier-Journal, 20 Dec. 2021 Naruto is an action-adventure series about a young ninja who dreams of becoming the leader of his village. Jacob Siegal, BGR, 18 Dec. 2021 There, the Keeping Up with the Kardashians alum coordinated her outfit with her son in matching head-to-toe black, captioning the post with two ninja emojis. Nicholas Rice,, 5 Dec. 2021 Clint made plenty of enemies while secretly operating as the mysterious ninja vigilante, and those enemies now think Kate has ties to Ronin. Los Angeles Times, 1 Dec. 2021 At the 250-room Legoland Hotel on the park grounds, rooms are family-size and come in themes like pirate, ninja, medieval castle. New York Times, 1 Oct. 2021 The hilltop wonder serves as Tiger Tanaka’s ninja training school in the fifth James Bond film, where Bond himself seeks combat training to confront the villainous Blofeld. Shelby Knick, Forbes, 20 Oct. 2021 There is the shine of the headlights and the sounds of a car rumbling down your street, no matter how much of a driving ninja the AI might be. Lance Eliot, Forbes, 10 Oct. 2021

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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Last Updated

4 Jan 2022

Cite this Entry

“Ninja.” Dictionary, Merriam-Webster, Accessed 28 Jan. 2022.

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More Definitions for ninja



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


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