Mook (noun) Originally referred to an Italian-American male; similar to Mick in reference to an Irish-American male; Modern use extends beyond ethnicity, gender, and income levels to refer to a average person inclined not to be athletically or mentally gifted, especially in the moment or during a particular situation. Mook is used as either a humorous (knucklehead) or derrogative (jerk) expression of humanistic imperfection or inappropriatness, such as to describe a person's clumsiness or loudness. The word is most often heard in the NE region of the United States, particularly New York City, Atlantic City, Philadelphia, and Boston.
Hear "What a mook!" in a ballpark when a baseball player drops an easy fly ball or to describe a person having no worldly knowledge beyond his neighborhood. Two brothers reply "...because we are just a couple of Mooks!" when asked why after graduating from elite universities they ended up doing PBS talk radio about automobile repairs. The word mook is best applied with a Bronx, Philly, or New Jersey shore accent.