What is the meaning of Ninja?

One trained in ninjutsu, especially one used for espionage, assassination, and other tasks requiring stealth during Japan's shogunate period.

One who very skillful, considered similar to the historical ninja, especially in covert or stealthy operation.

A notional draconian arm of a corporation (originally Nintendo), tasked with dealing with individuals that infringe on its rights or do not comply with its regulations.

A programmer or tech worker, particularly one skilled in a particular programming language or environment; used especially in job adverts.

One who is considered to resemble the historical ninja in some way.

2. An amateur private miner in Mongolia.

An amateur private miner in Mongolia.

Synonym of nigga, used as a friendly term of address.

1. Synonym of man; used as a friendly term of address.

   Synonym of man; used as a friendly term of address.

   Synonym of nigger.

   Fast and sneaky.

   To act or move like a ninja, particularly with regard to a combination of speed, power, and stealth.

   to beat someone to a post; to make the same reply just before the other party finishes typing, making their response redundant.

   To claim an item through abuse of game mechanics.

   ninja (spy and mercenary in pre-modern Japan)

   ninja (spy and mercenary in pre-modern Japan)

   ninja (spy and mercenary in pre-modern Japan)

   unidentified assassin with black clothes and mask

   ninja (spy and mercenary in pre-modern Japan)

   Rōmaji transcription of にんじゃ

   ninja (spy and mercenary in pre-modern Japan)

   ninja (spy and mercenary in pre-modern Japan)

   ninja (one who is very skillful)

   ninja (spy and mercenary in pre-modern Japan)

   ninja (spy and mercenary in pre-modern Japan)

   ninja (spy and mercenary in pre-modern Japan)

   Source: wiktionary.org