Also:
Derogatory term used by Italian-Americans, as portrayed by Hollywood actors. A mook normally is a jerk, schmuck or idiot. I've heard it used to describe other Italians or African-Americans in a rude and oafish way.
Also, a mook is a wooden dummy used by practitioners of Wing Chun Kung Fu. The full name is Mook Yan Chong (aka Wing Chun Wooden Dummy).