A ninja was a skilled fighter in feudal Japan, starting in the fourteenth or fifteenth century. Today, people like to call themselves ninjas for doing anything well — from making a touchdown to surviving a treacherous obstacle course.
The original ninjas were mercenary warriors and spies, and the methods they used were looked down on and considered dishonorable by the highest caste, the samurais. Ninjas were so fascinating and frequently discussed that they gained mythological status — in stories, people credited them with invisibility and the ability to walk on water, among other skills. In Japanese, the word ninja means “spy.”
a member of the ninja who were trained in martial arts and hired for espionage or sabotage or assassinations; a person skilled in ninjutsu
a class of 14th century Japanese who were trained in martial arts and were hired for espionage and assassinations