ninja

The word “ninja” means historically, a covert agent in feudal Japan trained in stealth, espionage, and combat. In plain terms, a stealthy historical Japanese agent, or informally, anyone impressively fast, sneaky, or skilled.

“Ninja” is pronounced NIHND-zhuh (/ˈnɪnd͡ʒə/ in IPA).

Here is “ninja” used in a sentence: “The museum exhibit displayed weapons once used by real ninja.”

Words with a similar meaning to “ninja” include killer, spy, superspy, magician and secret agent.

Depending on how it is used, “ninja” can be a noun and a verb.

The word “ninja” dates back to around 1900 and comes from Japanese. Borrowed from Japanese ninja (忍者), popularized in the West largely through films and novels of the late 20th century.

“Ninja” is a fairly common word in modern English.

“Ninja” has 3 distinct senses listed in this dictionary. The most common is: historically, a covert agent in feudal Japan trained in stealth, espionage, and combat.

Samurai were the noble warrior class of feudal Japan who fought openly under a code of honor. Ninja were covert agents trained in stealth, espionage, and combat, working in secret rather than in open battle.

In internet slang, to 'ninja' someone means to post a reply just before they finish theirs, making their almost-completed response redundant. It draws on the idea of acting with speed and going unnoticed.

The plural is often 'ninja,' unchanged, following the Japanese original. The form 'ninjas' is also widely accepted in casual English.

Both refer to the covert agents of feudal Japan. 'Shinobi' is the reading more commonly used in Japanese, while 'ninja' became the popular term in English and around the world.