What does ANBU mean?

ANBU meaning in Urban Dictionary

1. ANBU is a japanese business that has several anime such Naruto and FMA.2. A ninja position in an anime called Naruto. They are the greatest ranking of ninja in short supply of hokage (the best choice of ninja) additionally the sannin (the three strongest ninja that arn't hokage). They're secretive to the stage in which unique village does not understand their particular identities.