nin·ja /ˈnɪnʤə, (ˌ)ʤɑ/
  ninja
       n 1: a member of the ninja who were trained in martial arts and
            hired for espionage or sabotage or assassinations; a
            person skilled in ninjutsu
       2: a class of 14th century Japanese who were trained in martial
          arts and were hired for espionage and assassinations