What does 忍者 mean?
忍者 is a Japanese noun meaning “ninja; person trained in ninjutsu and employed for covert purposes in feudal Japan” in English. It is written as 忍者 in kanji, にんじゃ in hiragana, and ninja in romaji. This word is part of JLPT N2 vocabulary.
Example sentence
忍者ごっこをしよう。
Let's make believe we're ninjas.