so was this abbreviation invented in naruto, or was it something in the jap language alreadyOriginally posted by: Elessar
The japanese knows quite a few words for assassin - koroshiya, ansatsumono, kyoukan, shikaku - to name a few.
ANBU is an abbreviation for "ansatsu senjutsu tokushu butai" which means something like "special assassination and tactics unit". Just think of it as the SWAT [Special Weapons And Tactics] of the naruto world. If I'm not mistaken.
Btw, "anbu" is "dark side" in everyday-life-japanese.