ninjutsu
Concise Oxford English Dictionary © 2008 Oxford University Press:
ninjutsu /nɪnˈdʒʌtsuː/
▶noun the traditional Japanese technique of espionage, characterized by stealth and camouflage.
– origin Japanese, from nin ‘stealth’ + jutsu ‘art, science’.
'ninjutsu' also found in these Oxford entries:

